March 22, 2007

Tool Car

Riser legs clamped for welding to tool rack

On this day Joel C. continued fabrication work on the tool cart. Today’s project was to make the two racks for the long handled shovels. These required an extension above the main tool rack to accommodate the long handles. The extension was made from leftover pieces of the small 3” I-beam section that is used elsewhere for the reproduction mast arms the Association has made for the Sacramento Northern electrification project. The pins to hold the shovels were made from 1” steel round bar, the same as the other pins on the rack.

Tool rack ready for final assembly on cart

The parts were measured and cut, deburred, and welded together. Also, the extension legs which will hold the rack above the tool cart deck were welded to the cross bar. The next step will be to mount the rack on the cart, which means that it is almost complete.

March 19, 2007

Oil change for the Ballast Regulator
Today’s project is to do a little preventative maintenance on the ballast regulator. It needs an oil change, as well as checking various fluids. Fortunately, the pit track in the shop is open, which makes this work much easier. The machine was moved into the shop, and work began by draining the engine oil.

Ballast regulator in the shop for an oil change

While the oil was draining, Joel C. cleaned some of the dust and muck off the engine. This machine generates huge amounts of dust, and the smallest oil leak becomes an instant dust magnet. Being an older machine, of course, it has its share of oil leaks around the engine and hydraulic components. The goal here was to get things clean enough to avoid introducing dirt into the engine or other parts while the filters were being changed.

There are plenty of filters! The machine has 7 filters to be changed: two fuel filters, one engine oil filter, two hydraulic filters, and two air filters. Changing all of these regularly will help make the machine last longer. Joel also took advantage of the pit to grease the drive shafts, and check the oil in the transmission and differentials. Everything checked out OK on the underside.

With new filters in place, the crankcase was filled with fresh oil, topped off to the full mark, and the day’s maintenance project was done.

March 17, 2007

Track Crew work party

Bob P. and Mike W. set jacks on Track 33

Tamping in the Car House Three yard
The day before, Joel C. was able to pick up the repaired piston rod at the

hydraulic shop in Berkeley. With the new seals during the week purchased earlier, he set about to reassemble the cylinder. Everything went together smoothly, and the cylinder was mounted on the tamper just about the time everyone was showing up for the day’s work. Once the various connections were made for the cylinder, it was tested and the machine was ready to go to work.

Robert P. running the tamper

First order of business was to tamp off the track (32) in the new Car House Three yard where the Track Crew left off last time when the cylinder broke. Then the jacks were moved over to the next track (33), and that track was raised and tamped. In the photo, you can see the tamper hard at work tamping track 32 while Bob P. and Mike W. set the jacks to raise track 33. This track was tamped quickly, and the tamping was done! Well, at least the first pass was done. There will be additional work to be done with the tamper, but it can wait. Right now, the Track Crew needs to focus on the work necessary to allow the building contractor to return and finish up the concrete and paving around the tracks.

Robert P. gluing rail cushions

To this end, the Crew moved on to installing the rail cushions where each of the six tracks will be embedded in concrete. These rubber pads will provide a cushion between the rails and the concrete, something like a tie pad on a concrete tie. The rails will be embedded where the pedestrian walkway crosses the track at the north end of the building. With the weight of trains passing over, the rails will flex a little. If there were no cushion for the concrete, it would be pulverized by the flexing of the rails. The rubber pads will provide this cushion. The Track Crew for this day was Joel C., Wayne M., Bob P., Robert P., and Mike W.

SN 654 Test Run

Finally, at the end of the day, the Track Crew joined the shop crew for a test run of the Sacramento Northern locomotive 654. It was such a nice spring day – sunny, warm, and with green everywhere – and it was really nice to see the 654 out and about after so many years in the shop. It’s looking really sharp with the new paint.

March 15, 2007

Repairs to the tamper, continued

Broken part with sketch

Cutting off the old trunion

Roughing out the new trunion piece

Boring the new trunion piece

Set up for welding

Today’s work was to make the repairs to the hydraulic cylinder. The first job was to machine a new trunion piece on the lathe. Starting with piece of steel bar stock, Joel C. began by turning the round trunions at each end. In the photo you can see the broken piece with the sketch made of the piece needed. Next he put the cylinder in the lathe and cut off the welds holding the old trunion in place. Then it could be slipped off the end of the cylinder. This allowed verification of the size of the hole through the center, which needs to fit over the cylinder. Having verified the hole dimensions, the new trunion piece went back in the lathe and was bored to fit. Now it could be set up and welded.

For welding, the new piece was carefully aligned on the cylinder tube. It wouldn’t be any good to go to all this trouble, but then have the new piece misaligned, causing further trouble! By clamping the cylinder tube on our heavy T-slot table and making various measurements from the cylinder head, it was determined that the new part was squarely installed. Once clamped in place, Joel welded it to the tube.

Now it was necessary to face the issue of distortion due to welding. There was a slightly detectable warping on the inside of the cylinder bore, so Joel decided to clean it up with a cylinder hone. After working on it for a while, however, he decided that the scratches left by the hone were more than were appropriate given the soft nature of the Teflon seals that run against this surface. The next attempt was to remove the scratches using lapping compound on a cloth. The compound was smeared on a cloth, which was wrapped it around a large dowel, and plunged it in and out of the cylinder. After doing this for a while, some but not all of the scratches were removed. Joel decided that this would be good enough for now, though eventually the piston seals will probably be worn out since they will be running against a scratched bore. While this will work for a while, the real answer is to order a new cylinder. Since the manufacturer wants 6 weeks to make a new one, the repaired cylinder will have to make do while waiting for the replacement.

March 12, 2007

Repairs to the tamper, continued
Today, Joel C. was able to remove the offending hydraulic cylinder, and dismantle it for repairs. He has decided to repair the cylinder by machining a new trunion piece, and welding it in place on the cylinder. There is some concern about distortion of the cylinder due to the heat of welding, but it may be possible to overcome with honing. The photo shows the fracture in the trunion which resulted in failure.

Broken trunion on cylinder from tamper

March 8, 2007

Repairs to the tamper
Well, Joel C. ordered a replacement solenoid/hydraulic valve and installed it, without any improvement to the operation of the machine. It seems that this wasn’t the actual problem. The photo shows the area on the top of the tamper where the valves are located. The offending valve has been removed – it bolts up to the manifold in the spot second from the right. Anyway, after some head scratching and poking around, the real problem became apparent. It seems that the hydraulic cylinder that lifts the workheads on the right hand side is broken. The cylinder has a trunion near the top of the barrel which supports the cylinder (and therefore the weight of the workhead – quite heavy!) and one of the projecting lugs of the trunion is broken off. Since one of the two lugs is missing, when the cylinder tried to lift the weight of the workhead during operation, it twisted to one side, bending the piston rod. This then jammed in the cylinder, refusing to go up.

Solenoid/hydraulic valves for tamper

Calling around to various used equipment dealers revealed no used cylinders available. It seems that the Jackson model 2800 was a relatively rare machine, so not that many are sitting in a scrap yard being parted out. Calling the manufacturer (originally Jackson Vibrators, now called Harsco Track Technologies) revealed that they don’t have any such cylinders on the shelf, nor have they ever made one for spare parts. They offered to manufacture one, but it will take a week or so for them just to dig up the drawings and get a quote on the fabrication cost. No doubt it will be priced accordingly, and will take a long time to be fabricated.

Meanwhile, Joel has been consulting with the shop crew about possible ways to repair the cylinder we have. Clearly, the trunion weldment will need to be replaced, as well as the piston rod. The piston rod could be replaced by a hydraulic repair shop. The more difficult problem would be the trunion. The design doesn’t lend itself to easy replacement. However, it is conceivable that a new trunion could be machined in our shop. Then the old one could be cut off, and the new one welded in place on the cylinder barrel. In the mean time, the tamper remains out of service.

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