Steam Department

After a hard day at the shop it is always good to be able to say that we achieved what we set out to do.  Having a major target in sight certainly encourages you to keep going!

On 1630:

All the small tubes below the super heaters are now completely installed to the point at which we will first test them.  (As mentioned previously, they should be water tight after expanding and flaring.  So we aim to do an initial hydro test to identify any that need to be tightened before we roll over (bead) the ends of those that need to be so treated).

Tubing progress 03/16/2013

·         A number of us took turns to expand the firebox tube ends with the air hammer.  The technique developed last week worked well.  Brian rolled any tubes that showed signs of moving during expansion a little more to ensure they were tight.  He has become our expert with the tube roller, having expanded almost all the ends into the front tube sheet.

The expansion is a tough job.  It takes a lot of effort to control the large air hammer and ensure that a smooth flare is produced.  All this must be done while squeezed in above the arch tubes where the heat builds up nicely.  However, we found that you could do 6 to 8 before running out of steam.  As you weaken, you are able to apply less force to the hammer and the flaring becomes less effective.  So the time to stop is pretty clear!!.  Anyway, by constantly switching operator, we achieved the objective and flared more than 130 tubes in the day.

Here you see Phil and Brian at the end of the job.  In this case Phil operates the hammer while Brian watches the tube end closely for any sign of movement.  This is critical as the guy on the hammer cannot easily see if the tube starts to move;

Brian and Phil flaring tube ends

Phil flaring the last one

Meanwhile Mike and Ralph worked on the holes thru which the patch will be riveted to the mud ring.  The preparation is everything.  The hot rivet is hammered into its hole in maybe 25 seconds.  However the shape it will take is determined by forming the hole and the design specifies that the rivets are not all the same.  Some have conical heads with a small countersink into the sheet, while others are countersunk almost flush.

Here Mike is cutting the countersink into which the rivet will be formed.

Mike makes the countersink for a rivet

So, as is the way with this work, we now move on from techniques with which we have become familiar to new ones.  The next step on the tubing is to fit the 16 large super heater flues (and the remaining 9 small tubes that lie between them).  While the general principles are the same, the tools are distinctly different.  You certainly cannot use an expander on a tube this size.  Both ends and the ferrules at the firebox end will need to be rolled into place and these rollers are on a whole different scale from those we have been using.

On 428:

·         Dennis continued with building up the truck axles boxes.  The focus this week was on building up the ledges on which the grease cellar rests to provide lubrication to the journal from below;

Dennis builds up truck axle box

·         While Dave and Phil continued building the machining guide to mount the axle box wedges in the shaper. 

Elsehwere in the shop:

·         A big visible step was made on the wheel lathe.  The large gear, that was cracked and has been repaired, was finally fitted into place along with the clutch mechanism.  The mechanism was broken, either when the lathe was acquired or in transit, and has been rebuilt with some missing and broken parts reconstructed from drawings.  The gear is driven by an electric motor (behind the gear itself) and free wheels on the shaft unless the clutch is engaged (from a lever at the operator's station.  The control linkage was also reinstalled and can be seen running across the end of the lathe to the clutch mechanism.  Much to the relief of all involved, this now operates correctly when the control lever is moved!.

Lathe gearing back in place

·         Stu, Bob and Eric positioned the planer.  This may not look much but is a big step in activating this machine.  This a very substantial weight that has, to this point, been resting on rollers.  It has now to be finally positioned and leveled after which the rebuilt hydraulics can be reconnected.  During the afternoon and evening the machine was positioned.  Then the leveling screws were all cleaned up and located on steel plates.  The machine was the raised off the rollers and slowly lowered  so that it sits only on the leveling screws.  Next it will need to be accurately leveled (it currently demonstrates that the floor is not accurately level!) and locked into place.

Here you can see the early stages as Stu screws down one of the leveling screws to lift the main body of the planer and release the rollers that are still seen projecting from under the machine

Setting the planer

So next week we can start the next phase of the tubing.

Nigel