Sacramento Northern 1005 Restoration

Insulation, Old School: Wax Impregnating Maple

2010-12-17T00:01:00.000-08:00

Apologies for the long gap. We are back!

Here's a challenge. Making a good custom-built insulating panel in 1910, without use of asbestos, custom ceramics, or plastics.

The great minds of the age started with wood. Tests were done and it was found that maple, a hardwood, was the best combination of strength, workability and a natural insulator. Except, of course, when it was wet. And wood is always somewhat wet. If you dry it out entirely, it cracks, and in any case, reabsorbs moisture from the air over time.

The idea was struck to use paraffin wax to offset the water. But how? Even if you melt it on, there's still water within the wood.

Experiments were tried with VPI (vacuum pressure impregnation). In this, the unit is dipped in resin, set in a pressure vessel, and a vacuum is drawn. Water boils at about 75 degrees F in a vacuum, so it boils off, the vapor taken in by the vacuum pump. There is literally nothing in the voids, so when vacuum is released (and shop air pressure applied), the resin is sucked into the voids. It's a great theory, it works on metal machines like traction motors. But alas - not wood!

As it happens, liquid wax is happily above the boiling temperature of water. So of course, they had tried simply immersing the wood in hot wax. Above 212 degrees, the water boils off nicely, replaced not with a void, but water vapor. When it cools, this vapor condenses to a tiny amount of water, creating a vacuum that should draw in the wax. Assuming the wax had not turned solid!

In the early days of electric equipment, a great deal of testing had been done on this. They examined wax saturation and insulation quality. With help from the railway preservation community at large, BAERA volunteers had done some research on this.

It turns out there was a very particular pattern of temperature control that was required - heating to high temperature to drive off water, then a lower temperature to allow wax to absorb. The sequence took several hours.

It was within the range of a common (nowadays) electric skillet. The board barely fit! Here we see it at the end of the cycle, the wax re-frozen.

One might look at the picture and think: "OK! Turn it back on, come back in 20 minutes, and fish the board out of the wax!" No. After it was out, the wax would flow out of the wood. In fact, the board must be removed with the greatest care - the wax can be barely softened, and heated with spot heat from a "hair dryer" just enough to wipe the excess away.

The wood has already been machined (drilled). This was a product of careful and repeated fitting to the car. Even with the refinement of these techniques, wax impregnation is far from complete. Machining afterward would have exposed areas of poor penetration.

1005 in repose

2010-06-21T19:38:00.001-07:00

Here is SN 1005 parked outside Carbarn 3 for Member's Day. The lower panels are being prepped for paint. The other side is already painted. The car looks good!

What's going on with 1005? First, a complex repair on the brackets which hold up the radial coupler - a lot more on that job is coming. Second, the seats are being sent out for re-upholstery.

Why does it look so good while being parked in the dusty shop? It's kept under plastic. Here you see ropes set up to lift the plastic off the car.

Video of early shakedown run

2010-05-28T21:43:00.000-07:00

Last month the car was operated on its own, for the purpose of turning the car around and doing testing of the propulsion system and brakes.

A video of excellent quality was captured, and is located here.

http://www.youtube.com/watch?v=LCWWFkvGlSU

Overhauling the brakes

2010-05-11T13:32:00.000-07:00

Let's review some earlier work. Many of the components of 1005's brake system have enjoyed an overhaul. Now we get a glimpse of the teardown of the brake cylinder. No, it hasn't been since 1956. You can see in the picture below, the innards of the cylinder.

Center is the piston itself, which moves inside the housing. The plate above it clamps a large rubber gasket. You can see the gasket on the edge of the picture being held by a volunteer.

Upper left is the non-pressure head of the cylinder, also viewable on the left side of the piston in the picture above. As you can see, it guides the piston and gives the spring a place to nest. The spring is a return spring, which assures the piston returns to its seat when pressure is released. Among other benefits, this also protects the piston shaft from the weather.

A hand powered forklift was used to lower the relevant sections from the car - as they are heavy. Parts were cleaned and painted, gasket renewed, and reassembled and returned to service.

IT RUNS!

2010-04-15T14:23:00.000-07:00

Dave Johnston reports: Yesterday afternoon SN 1005 was switched out of the shop in order to turn it around so the coupler can be installed at the rear of the car. The car was moved off shop track 2 and placed under trolley wire by diesel locomotive VE 502. Then the pole on 1005 was placed on the wire and the dynamotor compressors pumped the car up. With a small group of shop staff on board, the 1005 made two trips down the tail track and around the loop under its own power. With the exception of a sticky whistle valve, the car operated flawlessly. This is the first operation of the 1005 in over ten years.

The brake system has been converted back to the M 24 A and M2 B brake valves, which operated much better that the system it had since its Key System days. Work still needing to be done includes seat upholstery, upper sash, final paint, rear coupler, and lots of details.

IT MOVED!

2010-03-18T01:06:00.001-07:00

Sacramento Northern 1005 has moved under its own power! For the first time in a decade.

The reverser is complete and tested, and the wiring is intact.

If you were at Members Day, you know the PCC and caboose switched places in the shop. At that time, the truck was moved under the car, and work was completed on wiring the reverser.

The motors were jacked up, and one at a time, energized to confirm that they turn in the correct direction.

The car was lowered off its jacks. The four jacks, including the damaged jack, are now out from under the car.

Tuesday, insulating the traction motor wiring was completed.

Today, power was applied and the car moved. Only 8 feet, but one giant leap for the project.

Spaghetti at the Western

2010-03-04T08:26:00.000-08:00

The reverser side rails are back and it's time to reassemble the reverser. Excuse this somewhat boring blog posting, it will simply contain the pictures the shop crew needs to rewire the unit correctly. Click on the picture to zoom in a lot.

Truck gets moved in place!

2010-02-19T18:13:00.000-08:00

On Wednesday, the power truck is moved underneath the 1005. That means all the work on wiring, piping, electrical and painting is complete. Note how nice it looks in fresh new paint. All the painting was done by hand. Note the caboose behind is quickly coming into paint itself. We call it "Sacramento Northern 1632" but its real road number is something else. The Western Pacific head office had ordered this caboose scrapped, but the yard crews decided this was in better shape than 1632. So they swapped numbers, sending the real 1632 to scrap in its stead.

Note how many people it takes to move the truck. Two people can keep it rolling with all their strength, but it takes a man with a lever to start it moving. This is in stark contrast to, say, a roller bearing caboose, where one man can move the whole caboose. That is because of the traction motors, which have a lot of rotating mass, and each have four plain bearings inside (two armature bearings and two where it hangs on the axle.)

Rest assured, this crew did not push the truck the whole way. They used the shop switcher, "Muni 0305", which lasted about two weeks on the Muni as a line car, but has proven to be a "really useful engine" around the WRM's shop. While they were switching, they exchanged Muni PCC 1016 and the so-called 1632 caboose. That puts 1016 over the pit for a traction motor swap. All three units are nearly completed, and the race is on to see which finishes first.

Here is the truck in place under the car. Photos this post by Joe Magruder.

Reverser Blues

2010-01-22T18:41:00.001-08:00

The 1005's reverser has gotten a lot of service and it's in great shape electrically. But it became apparent that the reverser frame is badly cracked. It was dropped for repair.

The reverser is located near the truck and on the centerline of the car. There should be no risk of the wheel hitting it as the truck pivots. However that might happen in a derailment, and from appearances, it has - at least twice.

Look at the lower right corner -- the damage is obvious. The side rail is cracked clean through, and the end case is slightly bent.

You can see the 16 wires that had to be disconnected. But that's not the hard part. The wires go through blocks -- these are not split "cleat blocks" like you saw before - these are solid blocks of wood. The wires can't be unthreaded from the blocks without unsoldering the end connectors. The best way was to remove each block, and its captured eight wires, as a set.

On the corners you see giant four-sided "bolt heads". That is exactly what they are - bolts with insulating material cast around the head. The rod is normal steel, but it's installed with an insulating sleeve and insulating washer. It insulates the hourglass-shaped casting which holds the electrical components of the reverser.

The spaghetti in the middle is important too. Obviously the wires must go to the same places. They must also be relaid in the same layers, otherwise the wires won't fit under the reverser lid! Careful notes were taken.

When the blocks of wood were removed, one cracked right down the middle. It was the damaged side, naturally.

The reverser case disassembled with ease, and soon, the side rails and end caps were separated. Off to the bead blaster. Several things are readily apparent.

The pieces are pushed together for the photo. They are broken clean. You can also see some other cracks. It's also clear one of the latches had been damaged, and was ground off and a new latch was fabricated. You can see where the part had been previously broken and braze-welded. This was surely a "shop job" done by the Sacramento Northern or Western Pacific. Brazing is used on cast iron because it is almost impossible to weld cast iron. The operative word is "almost", and the Western Railway Museum has had great success having cast iron castings weld repaired by a specialist, Lock-n-Stitch of Turlock, California. The pieces are now there, awaiting repair. The surviving good parts were sent along as well, as examples.

Finishing up the truck - commutators and cleat blocks

2010-01-22T11:48:00.000-08:00

No, this is not a new traction motor.

It's not even a "serviced" traction motor.

How does it look so good?

New fibreglass insulating cloth above the brush holders.
The armature was "stoned". That means it was machined down with an abrasive material (the stone). It was "turned on a lathe" - except in this case the lathe was the traction motor itself. The axle was jacked up so the motor could turn free, and the motor was energized with power from a welder.
The commutator bars were notched. Each of those little bars in the picture connects two adjacent windings in the armature. There is typically 10 or 20 volts between each bar. This is insulated by mica between the bars. The mica cannot be allowed to get above the commutator copper, or it can damage the brushes. Therefore it is notched down 1/16" or so, while foreign matter is also cleaned out of the grooves to prevent short circuits between them. There is a special tool made for this; however in skilled hands a hacksaw blade can do fine.
The commutator sides were painted with orange "Twin Pack" epoxy, discussed here.
The insulated mounts for the brush holders (off screen) were hand cleaned and painted with Awlgrip primer and topcoat.
The brush holders were removed and bead-blasted.
Brand new springs. You can't see them, but the fingers which press down on the brushes get their motive force from springs behind. The thing with custom springs is "it's $1000 to set up, then 50 cents a spring." Despite these four motors being the only known such motors in preservation,WRM got plenty of spares.
Yup, those are brand new brushes.

The black hole on the left of this picture is where the previous shots were taken. The armature is covered with black cloth to protect it. There you see the insulated brush holder mounts. Those have since been removed, cleaned up and painted. They look great. Click on any picture to zoom in.

The motor leads were re-sleeved with new cloth sleeves. This is not the insulation; they are also insulated inside. The sleeves protect the leads from abrasion. Despite the advanced age of the leads, the insulation was OK - partly because they had been in sleeves. In this picture you see the motor leads from both motors, so eight leads in all. All eight leads will loop upward at this point, you can see where they want to bend. The square sheet of material is "hard fiber" or "bone fiber", varnished, and protects the leads from the rough motor case, and the motor case from a possible short from an insulation-damaged lead.

You also see one of several cleat blocks. An earlier blog posting showed these in paint. Here they are on the car. You notice the the "lower" cleat block is longer, and is bolted onto the car separate from the "upper" cleat block. Why not just bolt them together onto the car?

Ah -- because we are upside down here! Normally, a cleat block is found on the bottom of the car, where gravity works against you. The longer, "lower" piece here would ordinarily be the upper piece. Bolting it to the car separately makes it a lot easier to work with, when you're under the car trying to push the heavy cables up into it, while also pushing the lower (here, upper) block onto them, and with your third and fourth hands, spinning on the nuts. You can imagine why they bolt them separately!

Speaking of bolts, those are not studs coming out of the upp-- wait, lo-- hrm, let's say longer cleat block. Those are square head bolts embedded in the block. The wood shop had notched out a square shaped space in the hardwood, so the bolt head is captured.

Cleat blocks are not standardized. Each one is made custom. This one started with a 2x2" stick of wood. Eight big holes were drilled for the wires. Five bolt holes, then the block was ripped edgewise. Unless the woodworker is very consistent, this cleat block will only mate with itself. That's something the paint shop needs to keep in mind when painting a bunch at once! Often a number is set into each half using a number die.

1005 Moves! Kinda

2010-01-16T17:09:00.000-08:00

One truck moved under its own power. Here's the YouTube video.

The problem was this. In a DC motor, most of the energy (watts) is consumed in the armature, and fairly little in the field. A series-wound motor has all current go through the armature, than all current through the motor field. So the field has very heavy windings. Each traction motor has four wires (two for armature and two for field). Three wires go to the reverser. That is so the reverser can reverse the field relative to the armature, as that is how you reverse a series-wound DC motor.

The 1005's wiring appeared to possibly have a serious defect. In one direction, the reverser would connect normally. But in the other, it would connect the two armature leads to each other, and the two field leads across the full 600 volts. The field's heavy windings were only ever designed to be in series with the amature. They would act like a near-dead short. Something would blow up -- one would hope, the fuse. Assuming that this defect existed, which it may not

So a test was made using low power. The reverser and Westinghouse HL switch group require 600 volts (which they drop to about 80 volts via a resistor ladder) for controls. They also require air to provide the "oomph" to throw the big contactors and the reverser. These controls were connected to trolley power, and to shop air. But we did not want to apply full trolley power to the questionably wired motors. Instead, the actual motor circuits were wired to a welder. It supplied about 60 volts - enough for the motor to barely turn on its own. The whine of the welder can be heard in the video.

Now, the car is high in the air on jacks. The north-end truck was beneath the north end. (the south end truck is being overhauled.) An "extension cord" was made to connect the four motor leads to one motor. Household 120/240 volt type wiring was used, as very little current would be needed for the test given the low voltage. Greg manned the controls, and took notches of power one at a time. The truck stepped to life and began rolling in the correct direction. Test done - shut off. It was tried in the reverse direction, and again the motor rolled. This would not have happened if the motor was miswired. Test complete, no trouble found!

Green Truck

2009-12-25T08:09:00.001-08:00

The SN 1005's second power truck is now fully painted. While the truck was primed in Awlgrip, this is an oil-based alkyd paint. In the cold shop, it is taking literally days to dry. The motor is tilted up merely to paint motor and truck. Wheels and axles are not painted because practice in the United States is not to paint them, to make the wheels easier to inspect for defects.

Look close at the roller bearings, and you notice two things. First, these are roller bearing axles. Second, the two casting ends are different and even bear different names. These facts are related.

One can guess that in 1912, this car was not built this way. Roller bearings were introduced in the 1930s as part of the plan to use the San Francisco Bay Bridge. The railway across the Bridge did not require roller bearings, but it did require cab signals. And those required speed control - which required speed detection. That was accomplished with a sensor inside the end cap of a roller bearing. The cap on the left is the stock Timken cover. The cap on the right is a special casting made by General Railway Signal company to serve the same purpose as the stock cover, and also house the speed sensor.

And so, all Sacramento Northern cab cars which meant to use the Bay Bridge had to be retrofitted with one roller bearing axle per car. If one is needed, why do we see two? Because near the end of the the life of these cars, the owner (at this point the Key System) swapped parts between cars on a regular basis. The newer retrofit axles had the best wheels on them, so they tended to be swapped onto surviving cars. Three out of the four axles on SN 1005 are roller bearing.

A thousand details are required to wrap up a restoration. One of them is securing loose air piping. Long pipe runs tend to rattle, and they need to be clamped to the car. A number of pipe clamps, blocks and spacers have been fabricated and are being fit to the car. The museum has special dies which can be placed in the hydraulic press, to bend hot-rolled steel bar to the shape of a pipe clamp.

Here are photos of the evolution of the truck.

Buffers and Pipes

2009-12-22T15:40:00.001-08:00

The buffers on 1005 were very badly rusted. It was all surface rust, but there was an awful lot of it. It's a job for a sandblaster.

Our beadblast cabinet is wonderful, but its glass beads are intended for lighter work, and the cabinet is intended for lighter (and smaller) pieces. So one of the volunteers funded sending it out to a commercial sandblaster and powder-coater.

Powder coating was not used in the "good old days". They would have if they could, because it is so much more efficient. It is applied as a powder and then heated to melt it onto the part. Click here to see how powder coating is applied. The gun "fluffs" the powder into the air, while imparting an electrostatic charge which draws it to the part. It's pretty easy to get a uniform coating, because a thick enough coating insulates the electrostatic charge, meaning new powder won't stick as well. But you have to get it right, a coating already baked on cannot be re-baked.

Once the part is coated, it is gently carried to an oven. Jarring the part would knock off the powder. It's typically baked at 400 degrees for 15-30 minutes depending on the part. The coating melts onto the part, giving a uniform, spray-like finish. No runs, drips or errors. One coat. And no toxins either - powder is relatively non-toxic compared to paint. Cleanup is easy, and if the shop is clean enough, spilled powder can even be reused. It is not a historic method though, so we don't tend to use it much.

Lastly, here is a bunch of the air piping under 1005, going to scrap. This gives you an idea how much piping was replaced during the restoration.

Let there be heat!

2009-12-11T23:45:00.000-08:00

Last Saturday was cold, but the SN 1005 crew was toasty warm. It was time to test the 1005's heaters. They worked without a hitch! Although... when a heater is started up after 10 years... it does make some funny smells.

The thermostat hadn't quite been worked out yet. The circuit for the thermostat is just the type of ingenuity you saw in those early electrical systems. SN 1005 does not have batteries. How do you make a 600 volt thermostat without exposing the public to hazardous voltages? The 600 volt current path is a ladder, going through two large power resistors, through the heater contactor coil, to ground. That circuit, alone, would have the heat run all the time. The thermostat is wired "across" the heater contactor coil. When the heat should turn of, the thermostat closes contact, shunting the coil. This causes the contactor to drop out. There is an additional resistor through the thermostat circuit, so some current continues through the contactor coil. They also included a snubbing capacitor to reduce arcing in the thermostat.

The crew also beeped out the #1 and #2 traction motor leads on the carbody, comparing the leads and their markings to the drawing. These were checked against the two traction motors on the truck being serviced. Those traction motor leads are being repaired, given new sleeves and new cleat blocks (made of wood - seen here in the poorly lit paint shop), which guide the traction motor cables.

The conductor's bell was also tested. You can hear it after the whistle and horn.

(the embed caused problems on some computers. Go here to hear the sound.)

At this point, if the Westinghouse HL controls are operated, the reverser will throw and the switch groups will click and clack, transitioning through resistor grids and series/parallel. Here is the switch sequence. Notice that several contactors have exactly the same sequence, i.e. S1 is always thrown at the same time as S2. In some cases, two contactors were wired in parallel for increased current capacity.

The No. 14 Double Check Valve

2009-12-06T09:39:00.000-08:00

Here is a drawing of a "No. 14 double check valve", one of many air-brake parts on the SN 1005. Many of these parts have come off 1005 for servicing. When this is done, the opportunity is also seized to paint both the parts and the piping.

In most cases, the parts are "hard plumbed" into the 1005's plumbing, which means a part comes off by following each pipe back to a union. The part comes off with an octopus of pipes attached. Here is an example of a double cutout cock, in which one handle closes two pipe circuits at once. The proximity of the ports makes piping a real challenge.

Before we are done, that part will be thoroughly cleaned externally, and overhauled internally - for this cutout cock, that means lapping the valve. And then, it will be painted - the valve will receive two coats of Awlgrip 545 primer then up to two coats of Awlgrip topcoat, "super jet black". The pipes will receive cold galvanizing compound, which will weather to the appearance of galvanized pipe.

Let's return to the No. 14 double check valve. Here you see a picture of WRM's spare unit. It is an interesting exception to the rule when it comes to "hard plumbing". As you may know, there was a major "shift in consciousness" about railcar plumbing. Now all the pipes go to a pipe bracket which is nothing but a manifold for attaching pipes. The device attaches with a gasket and a few bolts. It can easily be swapped, or carried as a unit to repair.

If you look above at the drawing, where you can see a clear separation line - above gasket #11. Is the upper piece really intended as a pipe bracket? A quick consultation of the parts list (below, off page) reveals that part #10 is indeed called a "pipe bracket". But you also see where the repairman had better know what he is doing if he means to unbolt the lower assembly from the pipe bracket - he's liable to have parts going everywhere. Clearly, pipe brackets have come a long way since.

Truckin' Along

2009-12-05T23:16:00.000-08:00

The truck is coming along. Here, you see one motor tipped up and out of the way, to allow painting of both motor and truck. Since the traction motor is nose-hung (half hung on the axle and half tied to the truck), this is very easy to do. Both motors have been painted, and the truck is being painted too. This is slower than you'd think. Scraping is the hard part. Media (i.e. sand) blasting cannot be used, because sand and blasted bits go absolutely everywhere and into everything. (Dry ice blasting is often touted as a solution to this, as the dry ice evaporates. However those blasted bits are just as bad as sand. The beauty of dry-ice is when when sending shop sweepings to hazmat disposal at $500/barrel.)

Applying paint on the intricate surfaces is also slow. A truck has a lot of surface area. But it's not just about paint. A lot of electrical work has been done on one of the motors, and the other will get the same. The commutator was cleaned, and the micas were re-grooved. Then the commutator and other areas were masked for painting. The area on either side of the commutator needs painting. The paint must have a high insulating value.

Twin-Pack is a two-part silicone epoxy coating. It comes in a box with two packs. That may be why they call it Twin-Pack. Or maybe because each pack is a very heavy plastic bag, with a clip in the middle. The clip separates the two parts of the epoxy. Remove it and knead the two parts together, then clip a corner and pour.

Trouble is, our stock was old. When mixed, it resulted in a heavy paste. The company only sells it in a minimum quantity of ten, um, Twin-Packs, and we use about one box per motor. So we sacrificed a Twin-Pack to the altar of science. What might be a compatible thinner, a solvent/diluent to reduce Twin-Pack to paintable consistency? Paint thinner resulted in only an angry emulsion. The same for mineral spirits, toluene, Awlgrip T0031 epoxy reducer, nor Imron reducer. Until - YES! Denatured ethanol did the job. A test paint yielded a very durable dry coat. So one of us played bartender, mixing up packs of epoxy as the painter needed it. The truck had to be moved several times to expose the relevant parts of the commutator.

3rd rail changeover - works!

2009-10-16T02:12:00.001-07:00

Good news from the shop. The third rail changeover switch has been tested under "live" operation and it works correctly, after a bad resistor or two was replaced.

You may recall the switch and its function were discussed at length here, with photos here.

Operation is fully automatic. The system detects the presence of third rail (with accompanying lack of trolley) and switches over. Or vice versa.

Keep on truckin'

2009-10-11T01:28:00.000-07:00

For your pleasure, here are some pictures of the truck, as it progresses.

Click on the pictures to see a much larger version.
Green is the final paint color for the truck. The ends were painted green early, so as to allow pieces of the truck to be bolted up.

2009-10-03T23:11:00.000-07:00

A previous post talked about the connecting air hoses and brackets. Significant work has gone into refurbishing those parts.

In most cases, the work needed is merely surface prep and paint. Last Saturday, the beadblast cabinet was in use continuously with people waiting for time on it.

In this particular case, three air pipes require three valves on each end, for six total. Every one needs "lapping". The valve is first pipe-plugged, then beadblasted with great care to keep beads out of the innards of the valve. Then the valve is disassembled and cleaned. Often, there are scratches on the surface of the valve, which will cause leaks.

The heart of the valve is this cone-shaped piece, which fits into a valve body of same proportions (below). Ignore the rod at the top, that's an improvised handle to make this job easier.

The cone is coated with lapping compound, which is an abrasive compound made into a slurry. Liquid sandpaper. The cone is then fitted into the valve body, rotated back and forth several times about 1/4 turn, lifted out, seated in a different place and rotated again. This constant reseating is necessary to avoid adding new scratches. Periodically the valve must be lifted out, washed off in solvent, and inspected. You only want to remove barely enough material to remove scratches. Finished, it looks like this.

Many other parts needed surface prep and painting. The primer used is Awlgrip 545 primer. This is a 2-part epoxy primer comparable to some of the best automotive finishes. Because it's designed for boats, it's designed to be brushed as well as sprayed. That's useful, because the safety precautions in spraying it are considerable, but with brushing it's mainly a matter of "don't get it on your skin". All the same can be said about Awlgrip Topcoat, the finish coat used on these parts.

The paint room was kept busy.

A peek at the truck

2009-09-10T10:09:00.000-07:00

Repairing the wreck damage on one end of SN 1005 required removing that truck. Because of the considerable air, electrical, frame and coupler work required, the truck has been stored outside (under tarp) until recently. Now with that work complete, it is time to prepare the truck for service.

Here it is, brought into the shop, and behind it is a real treat - freshly painted Muni 1016!

Note the third rail pickup assembly has been removed from this side.

Birney 62 is not in the shop for repair. The shop is a temporary carbarn while a culvert is dug under the yard of Carbarn 1. The culvert will correct a drainage problem and allow restoration of the duck pond.

Draft gear, redux

2009-09-09T21:17:00.000-07:00

The draft gear and couplers are a big job, and the work continues. Here, you see the coupler mated with its draft gear housing. The entire draft housing has been freshly painted with Awlgrip. You can see the hole on the right where it ties to the carbody and pivots. What you can't see is the draft gear including its essential spring, but it's a fairly conventional Janney arrangement. More on that later.

Here is the other, less freshly painted, draft gear mounted on the car - my apologies for the picture quality but it was very low-light. You can get a peek, through the side hole, of the outer draft gear spring - there's a second spring nested inside the first.

There are several interesting features in this shot. First, to the lower right, is a 3-way pivot arm directly on the coupler pivot point. It has three arms, which connect the cut levers on each side to the coupler itself. One of the cut levers was forged at a blacksmith (see previous post).

And on the upper left, you see a bracket. This is one of several brackets along the coupler. They carry three air pipes, and one heavy 600V jumper cable. Normally, connections like this come from the carbody. But on 1005, the connections are hung from the coupler shank itself, so they pivot as the car pivots. That means it won't part an air hose going around a sharp curve.

Here you see the brackets which ride closer to the coupler. This is where three air pipes connect to the air hoses and "glad hands". An electrical connection is made here as well; this carries third rail current down the train. Another connection, up high, trainlines trolley power.

The three air hoses are not the same as a locomotive. The first connection is, as you would expect, brake pipe. The second connection is a signal whistle, which allows the conductor to signal the motorman. The third connection is not main reservoir. It is called "control pipe", and it provides the air supply to the brake stand on a control trailer. In this configuration, the brake stand does not have a feed (reducing) valve - "control pipe" contains reduced pressure at the nominal brake pipe pressure.

Now, let's revisit the draft gear itself. Earlier this year, there was an RyPN discussion about couplers and draft gear on a narrow gauge car at the SPCRR, Society for Preservation of Carter Railroad, in Ardenwood, Fremont, CA.

Here's one of the narrow gauge couplers Randy was referring to. It's now the Sunday before Labor Day, and the coupler and draft gear is ready to reinstall in the NWP caboose. Here you see draft gear that is very similar to SN 1005's. In draft (pulling), the forces pull around the C-strap, compress the spring, which pushes against the left "ears" which press against the car. In buff (pushing), the forces push directly down the coupler and compress the spring, which pushes the right "ears". This entire assembly can be lifted by two men, rather unlike SN 1005's. The wooden blocks, I'm told, compensate for the draft gear having been converted from link-and-pin to knuckle many years ago.

Welding a cut lever - the old fashioned way

2009-09-06T19:16:00.000-07:00

To uncouple, you pull a cut lever. SN 1005 has four cut levers - one on each corner of the car. These connect through a link rod to the couplers themselves. They are made of about 1/4" steel rod.

Three of the cut levers were intact, and could be reused. The other one had been lost or destroyed, and had been replaced by an improvised cut lever which was functional, but not historically appropriate.

The original cut levers had been forge welded by a blacksmith. Fortunately, a blacksmith capable of the job operated at the Ardenwood farm in Fremont, California, and frequently did projects for the SPCRR, also at Ardenwood. Dave Johnston took the materials there. Here is a photo of the blacksmith shop.

And here is a photo of the crew at work (not on our cut lever)...

Riveting draft gear

2009-08-14T23:38:00.000-07:00

SN 1005's excursion career saw it shipped all over northern California in freight trains. It is not built as strongly as freight cars, so it tended to take the brunt of the damage in rough handling and switching accidents. Needless to say, a lot of this fell on the couplers and draft gear. Previously, both ends' couplers and draft gear had been disassembled. Subassemblies had been repaired, including a complex steel forging in the shape of a "C" which wraps around the draft gear springs. This is riveted to the coupler body with two large 1-1/4" rivets.

These rivets are special. They are flat-head rivets. They must lay flush against the draft gear when they are done. Their holes are countersunk with a bevel, so the rivet is shaped like a flat-head screw. It's that way on both sides.

What makes a rivet a rivet (and not a bolt) is that it is heated to yellow-hot, inserted into the hole, and hammered. This makes the rivet expand fully into the hole, leaving no space. If the hole is irregular, the rivet fills it all, at least near the hammered end. Most rivets start with their familiar button-head already on one end. But this rivet is flat-head. It must expand into a countersunk hole. To get a good start, the rivet is turned with the correct shape of head. Even so, this will be heated, and will deform and expand to fill the hole.

One of the tricks with any riveting job, and this one especially, is to compute the correct amount of metal to be in the rivet to expand into the hole and yet leave the correct amount of metal in the head. With button head rivets there are familiar formulas. Ah, but what volume of metal will fill that beveled countersink? That required the sharp pencil and a fair bit of calculating.

Another way to make the rivet fit is to drill out the hole. This was more complicated because the coupler body is hollow, so each hole through the coupler body is not continuous steel. When the hole picks up on the other side, it doesn't quite align. "Misaligned holes" is a common problem when riveting. (Especially when riveting bridges, hold that thought.) We started with drill bits, stepping up in 1/64" increments, which made the developing hole tend to center itself. The coup de grace was delivered by a bridge reamer. It has a tapered shank, which centers on a slightly misaligned hole, and aligns it by enlarging it. Our finishing size was 1 and 5/32", or 1/32" over nominal rivet size.

Another problem - how do you hold the rivet gun onto a flat-head rivet? On a normal button-head rivet, the rivet itself does the job. The shop crew created a solution: The C-shaped bar was steel, so it could be welded. They found a pipe that would just fit around the rivet gun. They cut about a 2-inch length of that pipe, and tack welded it in the right place to guide the rivet gun over the rivet. Problem solved!

On the first coupler, this preparatory work was done Tuesday. On Wednesday, the rivets were driven. The rivet must easily go into the hole when it is heated. Heating makes it bigger. Which is the idea behind drilling the hole 1/32" oversize. It wasn't enough - on our first try, the hot rivet would not go in the hole. It was let to cool, and 1/32" was turned off it on the lathe. It worked the second time. Lessons learned, the second rivet went in fine. A fair bit of grinding followed, and riveting is now complete on one coupler. You can barely tell there are rivets there.

Are the rivets in shear? No, they aren't. Coupler draft (tension) and buff (compression) both go through a big spring that goes in the empty space you see. More on that later.

Reverser repaired

2009-08-13T22:55:00.000-07:00

Over the previous week, the 1005's reverser drum was repaired, tested and reinstalled. The reverser's job is to reverse field connections on each of the traction motors. On a series-wound traction motor, the field is in series with the armature. That means every field must take full traction motor current, and thus, so must the reverser. It must have a circuit for each motor, i.e. four, and at least four contact blades per circuit.

This makes for a very big switch, and it's built as a multi-pole drum switch. Because of its size, it takes a lot of force to throw. The muscle actually comes from air. Electrical signals operate a "magnet valve" which applies air to a piston, which throws the drum switch over. There are two magnet valves, one for each direction. The electrical signal to each magnet valve goes through an interlock on the drum itself, which cuts power to the magnet valve (and thus air to the piston) once the drum reaches the desired position.

You may recall two articles (1) (2, photos) about the third rail changeover switch. This switches even more current, but only one circuit. They were usually reversers with their many contacts ganged together to increase current capacity.

The Westinghouse HL equipment also has switch groups, which is a footlocker-sized cabinet with 6-8 large contactors in it. 1005 in fact has two complete sets of switch groups; that's because the additional complexity of the 600/1500V changeover required more switches than one group contained. Al has been overhauling some of the switch groups. Here you see him working on some interlock fingers. These don't carry full traction current, but signaling current. Their job is to interlock other contactors which should never be closed at the same time, such as series/parallel transitions.

M.U. sockets complete

2009-07-25T21:20:00.000-07:00

The connections to the M.U. sockets have been tested and are complete. That says all the M.U. connections are correct, and by extension the control stands are correct. The testing is done with a very old "ringer box" containing two 6 volt batteries and an electromechanical bell connected to some very long wires. The ringer box proved persnickety and of course needed repair of its own.

One twist (literally) in the M.U. wiring is the forward/reverse controls. Forward on one controller is the same as reverse on the other controller. Similarly, the pin in the M.U. wiring for "forward" on one end, must be the pin for "reverse" on the other end. As you can imagine, there's only one way to resolve this: "twist" the forward and reverse pins halfway down the car, so forward goes to reverse and vice versa. But how does it get back to normal for the next car? Heh - there's also a twist in the M.U. jumper cable.

M.U. wiring complete

2009-07-15T21:22:00.000-07:00

Another big wiring job completed is the multiple unit wiring. This is the 12-pin jumper plug discussed earlier, and its numerous connections throughout the car.

The multiple-unit control plug carries signals which control forward/reverse, series/parallel and the various resistance points. This wiring must go to a remarkable number of places on the car. On each end, it goes to three places - motorman's control stand and also to two jumper plugs. The seventh connection is to the switch group which actually controls the car's motors.

These connections happen in three control boxes - one at each end and one in the middle of the car. The end control boxes connect to the motorman's control stand, two jumper plugs and the middle control box. The middle control box connects to the end control boxes and to the switch group. With 12 wires per connection, it gets pretty crowded in those boxes!

3rd rail changeover switch complete.

2009-07-15T21:15:00.000-07:00

The wiring for the changeover switch is complete. You can see the parts which have been reused and which had to be made from scratch. It was not possible to obtain a solid piece of maple large enough, so the drum is a glued composite. The latches are a stock item from McMaster-Carr.

Third rail changeover switch

2009-07-10T22:36:00.000-07:00

The 1005 is being restored to its 1934 configuration and appearance. In 1934, the Sacramento Northern operated on both overhead wire and third rail.

Electrically, it would be simplest to wire the trolley poles/pantographs to the third rail shoes at all times. However that is illegal and unwise. There must be a changeover switch that connects car power to the active one while isolating the other.

On the 1005, this is fully automatic. This is done with a pair of relays in the baggage compartment of the car. One relay picks up if power is present on the trolley wire. The other picks up if power is present on the third rail. If "trolley" is on and "third rail" is off, it energizes a wire which runs down to the changeover switch and says "switch to trolley". Or vice versa.

Alongside this relay box are four resistors. Two are dropping resistors for the two relays present in the box. The other pair are dropping resistors for the two wires going down to the changeover switch. One pair of resistors was fine (it was made of cartridge resistor elements which removed like a fuse.) The other pair was totally defective and new resistors had to be made. The order came in; it was wrong and had to be remade. They were further modified to replicate the original mounting style. This work was completed last week and the relay box and resistors are remounted in the baggage compartment.

The changeover switch is underneath the car. It processes each signal further. For instance if the "switch to trolley" signal is energized, it will switch to trolley, but only if it's not already in trolley, and only if the car is coasting (not motoring). If all conditions are met, the signal reaches a magnet valve, which applies air to muscle over a big rotary switch similar to a reverser. There is yet another interlock, which assures the switch will only operate when the car is configured for 600 volts DC (not 1500 volts DC).

As to the changeover switch itself, the restoration had a challenge.

Normally on a third rail car, all third rail shoes on the car are connected together electrically. Third rail shoes on one side are touching the third rail; on the other side they stick out, energized and dangerous. Crews in third rail territory are trained on this, and civilians are kept away. That is how SN 1005 was configured in 1934. The Key System bought the car in 1942. The Key used third rail to come over the Bay Bridge and into the San Francisco terminal, but they had low level platform loading. Passengers could easily touch a third rail shoe. So, Key required a more sophisticated changeover switch which isolated third rail shoes on each side of the car. They removed and scrapped the original changeover switch!

The correct changeover switch would have to be remade from scratch.

Changeover switches are very similar to reversers. The air motor, magnet valves and some other parts were scrounged from an old reverser. Outside of that, the changeover switch was built from scratch over the last two years, using the reverser on another car as a model. This was a considerable undertaking. It took about two years, and is complete. It has been installed and the heavy power connections have been made.

What remains is the small signal connections. At this writing, wiring has been pulled through conduit, between the changeover relays, the changeover switch, and the 600/1500 interlock.

What's in a plug? A challenging fabrication

2009-07-10T21:16:00.001-07:00

Interurbans such as the SN 1005 frequently ran together in trains. The motorman worked the controls in the first car, and all the cars with motors responded in sync to his actions. This is done through "multiple-unit control", or "M.U." A control cable runs the length of the train, and jumps from car to car via plugs.

Ah, the lowly plug. We use plugs and sockets for so many things in our society, but who ever thinks about them? You need four to charge a cell phone. Nowadays plastic insulates the various pins. But what do you suppose they did in 1910?

There's a surprising answer. Maple.

The Western Railway Museum plans to M.U. the 1005 with other units, such as the 1020. The M.U. plugs on 1005 needed work. The copper pins were shot (fabricating them is another story!) and the maple insulators were in poor shape. How do you make one of these?

It's not as simple as you'd think. All the holes must have a very particular relationship to the index key. If any of them are off, the plug won't mate. And we had several to make. (they are four inches in diameter.)

Two approaches were tried. Rather than try to machine each plug individually, one of our machinists made a steel "cap" which could fit over the insulator. In this cap, he carefully drilled holes in the right places. A tedious job, but done once, it provided a jig that properly located the holes for any piece. A second approach was explored in the digital realm: software that would tell a CNC router how to cut the part out of a block of wood. Software incompatibilities slowed that project, and the traditional machinist won. Jawn Henry would approve.

The insulators were drilled, shouldered and tapped 1/4-20 for the pins, which screw in. Maple is a hardwood which accepts threads well. These pieces are almost 2 inches thick, and tapping them required special nut taps.

Maple is already an excellent insulator, but only when dry. One way to solve that problem is to boil the maple in paraffin, driving water out and wax in. However, in this case, the pieces were painted with Glyptal paint designed for high insulation value. The pieces really "drank up" the Glyptal. Bolts were screwed into the threaded holes to "mask" them from the Glyptal. The bolts came out easily.

Soldering wires onto the pins was the next step. For each plug location, the crew measured the distance to the junction box, and they cut 12 wires of this length. They tinned 12 pins then cleaned the threads of each pin, screwed the pin into the maple block, and soldered a wire to it. It wasn't necessary to mark which wire went to which pin; the wiring crew will ring those out later. No ribbon cable here!

The twelve wires were threaded through a cast iron rear cap, then inserted into the back of the cast iron housing and the rear cap was installed. The result is the picture you see at the top.

Click on any picture to zoom in. This work was completed on June 30.

Pilots repainted - June 20, 2009

2009-07-10T12:14:00.000-07:00

One recent project is the repainting of the front and rear pilot. (some might call it a "cowcatcher".)

The pilots were removed from the car. They're too big for the beadblast cabinet, and sandblasting a large assembly out in the open is quite a dirty job. So the pilots were chipped by hand, it proved practical to remove all the old paint.

As always, the paint being used is Awlgrip 545 primer and Awlgrip topcoat. In this case the color is Super Jet Black.

Click on the pictures for a much bigger version.

This work was done about three weeks ago. The post is being done new because, well, it's a new weblog! Expect a few more back-dated entries to cover work recently done.

2009-07-09T09:59:00.000-07:00

Welcome to the weblog of the SN 1005 restoration, a project of the Bay Area Electric Railroad Association.

Sacramento Northern 1005 is an electric interurban car, one of the first acquired by the Association. It is a sentimental favorite among members, as it was prominently used in railfan excursions on the Key System and Sacramento Northern in the early days of the Association.

The car was stored in Oakland, but many of the excursions were in distant areas. This meant 1005 rode a lot of freight trains getting there. The 1005 is more fragile than a freight car, even though its couplers and brakes are compatible. This led to incidents of damage. The most severe was in 1962, when the center sills were badly bent. The Western Pacific Railroad moved it to their shop for repair, but after long study, considered the car too far gone.

Enter car 1020, another excursion regular. 1020 had been built as a trailer and converted to a motor. During a fan excursion in the 1950s, its electrical gear caught fire,and it was converted back to a trailer. The railroad offered both 1005 and 1020 in settlement for 1005's damage, with the notion that museum volunteers could strip the electrical gear from 1005 to remotor 1020.

The Association did not do that. 1020 remains a trailer. 1005 was used in limited fashion despite its damage.

And here, the phoenix story begins. In 1999, the Elliot R. Donnelley Family Trust offered $75,000 to restore 1005, and work began in earnest. The damaged frame sections were replaced. Restoration expert Glenn Guerra was brought on board. Virtually all of the woodwork below the ceiling was replaced. Windows, seats, mechanical and electrical work continues to this day. About $250,000 and 20,000 man-hours have gone into the project.

Most of the work is now done. The project is in its finishing stages. There are still a lot of interesting things going on, though. This weblog aims to document some of them.

Above is a picture of the car as of July 5, 2008.