Entries by Nigel Bennett

A brief update this week.  Labor Day weekend meant a small number at the steam shop this Saturday but steady progress continued on 1630 and other areas.  Much of the work was continuation of tasks previously described so no new pictures this week.

On 1630 a major step is that we now have a firm date for the FRA inspection.  This is scheduled for Saturday 9/15.  If this is satisfactory a number of major tasks on the boiler can kick off immediately and we are focused on getting prepared for these.

·         Collin spent the day doing a final "pre-inspection" ensuring that all parts of the boiler shell are fully clean, visible and free of any damage or cracks.  This involved some needle chipping to remove small residual areas of scale and a great deal of vacuuming to remove odd residual pockets of sand blast medium.  All the remaining tools and oddments, used during activities over the last several months, were removed so access is free and clear.

·         We also cleared the footplate, smoke box and walkways of equipment that is no longer required so she is tidier and more accessible than for several months past.

·         I checked out the supply of the Apexior coating, that we will apply to the interior of the boiler after inspection.  This is a lovely material, which I now know sticks to skin just as well as it does to boiler plate!.  Over the years it separates, producing a material with the consistency of tire rubber.  Anyway, after a lot of checking and a long time on the paint shaker, we now have a little over 2 gallons of the material in good condition.  This is enough for the area of the boiler interior so we are ready to go as soon as we have the all clear.

·         Another really tedious task was the sorting of the copper ferrules for the tube sheet.  The good news is that Tom has confirmed spares are readily available.  The bad news is that these apparently simple little rings will cost $6.50 each!.  Needless to say, not many of the large number we have are the right size.  I found another 25 and can console myself that the effort of sorting did at least save us $150.  However, we still need 150 more so that is a cost of around $1,000 that we had not been expecting.  Now if anyone has a boiler with 1 3/4 inch tubes and needs ferrules ........ IRM steam department may be in a position to cut a deal !!.

·         We continued working thru the tube expanding tools to ensure that all are clean and ready for tube fitting.

·         The job of cleaning the super heater element bolts continued and is now nearing completion.

·         Work continued on bending the firebox patch.  The template is now securely bolted to the mud ring and the next step will be to heat it and form it to the complex curve of the tube sheet.

On 428 the third axle box was loaded on to the turret lathe and much of the babbit was removed from this box.

In other areas:

·         Jeff worked on the plan and material requirements for installing the larger compressor and air supply system in the South end of the shop.  This is a project that may well be one of the investments of funds from the 2012 benefit concert.  It was on the list of possible projects but is moving up the priority list as the existing compressor seems to be using rapidly increasing quantities of oil.  Since much of what we do relies on the air supply, this is a great concern.  The project would also have safety and efficiency benefits as we are currently running 100 plus feet of hose whenever we use air in the South end of the shop.

·         We were able to assist the Track Department with the loan and set up of our magnetic drill (shown in recent pictures of removing bolts from the smoke box) as a simple way to make holes for the bolts required to extend the frame of their tamper to fit a larger motor.  The steam shop cannot conceal a vested interest in this project !!.  The track out to the wheel drop is in serious need of tamping to avoid risk of damage to the pit walls so we hope to see this machine in action soon.

So overall a lot going on as we set up for the inspection and all the major work that this will enable.

Nigel

The second weekend of Thomas and temperatures into the 90's predictably led to a slower work day at the steam shop.  However we are now seeing more clearly that work is shifting to the new phase of preparing for reassembly.

On 1630:

·         On Monday I met George, the welding specialist from Curtis Boiler, on site and he carried out the welding on the rear tube sheet.

·         As mentioned in previous, weeks this was the last critical step to be ready for internal inspection of the boiler by the FRA.  With this done, Collin spent Saturday morning cleaning and clearing tools from inside the boiler as well as carefully inspecting all the surfaces for any sign of cracks or damage and polishing any rough edges from the tube holes.  We can now advise the inspector that all is ready for inspection and hope that he will be able to fit us into his schedule in the near future.

·         Glenn and Richard did some rework on the safe ends for the super heater flues.  Inspection on Monday indicated that a couple of these had been cut from tube that was more pitted than desirable so new ones were made ready for welding to the flues in the next couple of weeks.

Glenn cuts the taper on a safe end

·         A good start was made on cleaning and preparing the nuts and bolts that secure the super heater elements to the header.  This is typical of a lot of work that we will be doing in the next few months.  These bolts fit into the header at the top of the smoke box so have a tough life, in the path of the exhaust gases from the fire.  To remove them required heating to red heat with the acetylene torch.  Now they must be thoroughly cleaned, the threads checked and re-cut as necessary, to ensure that they fit and tighten smoothly when we come to fit the elements.

Element securing bolts as removed

and after a good deal of TLC

·         Vince cleaned and lubricated and number of the flexible stays ends so we are now well on the way thru that process.

·         Kevin is back for a few days and continued with needle chipping the exterior of the boiler and support brackets so that we will be able to do a thorough re-paint.  He is at Union for several days so this activity will continue during the week.

·         Mike continued with test fitting of the patch.  This is a very tricky exercise, a sort of three dimensional jigsaw.  It looks as if we are now close with this test.  Once this is done, we will run thru a second test to prove that the principles developed can be applied reliably to and then we can hopefully produce the patch proper.

·         I worked with Tom on preparations for fitting the tubes to the boiler.  This is quite a complex, multistage, operation that you will hear a lot more about in the next couple of months!.  The first step of the process is to expand the ferrules (copper rings) fitted between the tube and the rear tube sheet into the holes before the swaged tube is fitted.  After working with the various sizes of ferrule that we have been sorting and measuring for the last couple of weeks it is clear that we have nowhere near enough of the most commonly required size.  We will determine in the next week if we can get ready made ferrules this size in a reasonable time.  Otherwise we do have the right size of copper tube and will need to start cutting about 200 of these little rings !!.  Good news, it is now clear that, once you know how to match the ferrule size to the hole, the fitting process can be rapid.  After all the measuring and testing I was able to fit the first 5 ferrules in no more than 10 minutes.  This is likely to be the pattern throughout this operation.  We know that years ago re-tubing a boiler was an remarkable fast process.  We will have to become familiar with each of the steps and then try to become efficient but accurate at carrying it out.

On 428:

·         Machining is speeding up on the axle box thrust bearings.  The first one is complete and the second nearly so.

Thrust bearing largely machined from a second axle box

Interesting.  The attachment to this box looks quite different from the first.  This seems to be a common factor with 428.  Each part has been differently repaired at different times.

Nigel

The number of volunteers at the Steam shop was lower this weekend as it usually is during Thomas weekends.  However some key tasks were completed.

On 1630:

·         The last of the troublesome smoke box bolts was removed.  With the bolts out, I was able to clean up all the holes and test fit new "T" bolts into all of them bar one.  The new bolts are now being ordered for 10 of the 11 holes.  The 11th requires more work.  The smoke box has clearly been reinforced since this one was fitted so a rivet is now positioned that prevents setting the bolt into the ring from the rear.  Tom will need to make a special stud that we can fit from the front and secure by welding a nut on the back.  However, this repair is now largely complete and ready for when we refit the smoke box front sheet.

All the problem bolts are out !!

·         All the flexible stay caps, that were marked as requiring removal, were successfully freed.  This requires heating the socket of the stay with a torch before unscrewing the cap.  Applying brute force to the socket wrench without using heat to loosen the thread is absolutely not recommended!.  Cracking or otherwise damaging the socket would mean that the whole stay must be removed by drilling it out of the inner firebox then rethreading and fitting a complete new stay - several days of work - so it is a big relief that all are now off with no damaged sockets.  One damaged cap was successfully removed and will be replaced with our last spare cap.  A few more will be ordered to ensure that we have some spares in hand.  The caps must be removed and the stays hammer tested where the stay does not have a full length tell tale hole.

All the caps to be removed are paint marked

Once the cap is removed you normally find rust, scale and debris that must be cleaned out to allow later hammer testing.

There is normally debris in the socket

Once clean you can get a good idea of how the stay operates.  In the center is the ball head of the stay, a long steel rod the other end of which is threaded into the inner firebox sheet  The slot in the ball would have been used when the stay was installed to turn the rod and so screw it into the inner firebox sheet.  The ball sits in the socket, which is welded to the outer firebox sheet.  Screwing the rod into the inner sheet tightens the balled end of the rod against the socket. 

As with rigid stays, the objective of the flexible stays is to hold the inner and outer firebox sheets together against the full pressure of the water and steam that lies between the sheets when the boiler is in service.  The difference is that flexis are used where it is calculated that there should be (marginal !) movement between the two plates as they expand  This would strain and potentially crack a rigid rod.  The movement of the ball in the socket allows this movement.

Tightening the ball into the socket provides a significant, but not complete, seal against the boiler pressure so the cap provides the final seal.  This is why there is likely to be some debris in the socket when you first remove the cap.

The socket cleaned ready for testing

·         Mike continued with test fitting of the patch.

·         We also started on the exercise of measuring the holes in the tube sheet and matching these to the ferrules that must be fitted before the tubes can be inserted.

·         Most importantly, it now looks as if we should have good news on the welding by next weekend.

On 428:

·         Machining is now well under way on the thrust bearing surface of the first axle box.

First axle box mounted on the turret lathe

This clearly shows the remains of the old thrust bearing which consisted of mesh (actually old spark arrestor mesh from the smoke box was specified in the UP drawing), which was tack welded to the face of the casting and held in place the babbit which was poured into the recess, allowed to set and then machined smooth.

·         The overhaul of the pump mechanism for the planer was completed.  The next step is to clean and test the hydraulic drive mechanism.

The hydraulic pump now ready to refit

Nigel