Steam Department Update 06-08-2013

I guess we would have to say that it was a reasonable rather than a good day of progress in the steam shop.  While we moved forward with the critical activity that we have been planning for several weeks, progress was not as good as we had hoped.  There was however real progress on the most critical work remaining to be done.

Obviously the main focus remains on 1630

·         Eric and Curt worked steadily at grinding the tube ends in the front tube sheet.  This is a tedious job, requiring care to ensure that the projection is reduced to 1/4 inch but no less.  They have now completed all but one of the super heater flues.  Good work guys!.

Eric relaxes after a hard day in the smokebox

·         Brian and David worked with Richard to install the wires to secure the insulation.  Wiring of the barrel is now largely complete.

·         Jane worked on cleaning and priming the small cladding plates.  These are used under the large sheets to seal around pipes and rods.  Given the number of projections from the boiler, there are a LOT of these, all of which need to be clean and painted ready for fitting.

·         The remaining large cladding sheets were lifted back onto the top of the machine shop to store until required.

·         All of which brings us to the main event !.  Work started on installing the rivets to finally secure the patch into the firebox corner and so complete the boiler shell.

Firstly a correction to last week, which demonstrates the dangers of documenting things that happen while you are not there !.  Having read last week's notes, Jerry pointed out that it was he, not Mike and Tom, who set up the timber staging to hold the bucker in the firebox. He even spent much of Memorial Day doing so.  Sorry Jerry, my bad.

Overall there are 13 rivets to be installed.  Of these 6 are not significantly countersunk into the sheets and have conical heads on the outside while 7 (those in and closest to the corner) are substantially countersunk (and have shallow rounded heads on the outside).  11 are ready to install while 2 more require some further welding work by Dennis (after the 11 are in)  before they can be fitted.  (To avoid confusion, the six domed heads already in place in the corner are not rivets but patch screws threaded into the mud ring.)  

Bolts were set into each of the holes to lock everything rigidly in place before setting the rivets.  One bolt is removed at a time and replaced with a rivet.  In this shot the first rivet has been fitted in the front sheet while bolts indicate the 12 remaining to be fitted.

The rivets to be fitted

Work started on the cone headed rivets, of which there are four in the front and two in the side.  Here two are fitted and the hole is ready for the third to be fitted.

Two in place

The heated rivet is passed to the team in the firebox and placed into its hole.  The end projects substantially thru the outer sheet.  The bucker is positioned behind it and activated to start hammering.  In this shot you can see the length of rivet that initially projects thru the sheet.

The rivet appears thru the hole

The hammer is carefully positioned on the projecting end.

The hammer is applied

Hammering compresses the hot rivet to form the head.  The time to do this is a matter of a few seconds as the contact with the mud ring and hammer cools the rivet very quickly,  As the rivet cools from the light yellow, at which it is placed, toward a dark yellow and then red it cannot be further shaped by hammering.

End of forming - see how much it is compressed

When the hammer is removed we can see the formed rivet head, still red hot.

The finished rivet still red hot

Forming the head of the rivet is rather like forcing back on a projecting cylinder of putty to form the required shape.  The challenge is that it must be driven back accurately so that the head remains centered on the shaft of the rivet.  If it once starts to bend, the force of the hammering will tend to accelerate the bending, resulting in a head offset from the body of the rivet that must be removed and replaced.

The four in the front sheet went in well with no failures. 

All 4 cone heads completed in front

Unfortunately the two in the side proved more problematic.  The first did bend in forming and produced an unacceptable result.  The head was ground off and, with a significant amount of work using the air hammers, was driven out, much to our relief as the greater concern is that it "mushrooms" in the hole and must be drilled out.  This hole will need to be cleaned up during the week before another rivet can be fitted.

Installation of the second rivet was attempted twice late in the evening.  In both cases we had problems with the air hammer forming the head, as a result of which the process was stopped before the rivet was seriously deformed.  So there should not be much problem in removing the rivet.  The problems with the hammer were resolved but, by 9:30 at night, operator exhaustion was a substantial risk factor and work was stopped for the day.

So nearly 1/3rd of the total are installed.  The disappointment is that, based upon initial progress, we had hoped that substantially more would have been completed.  So - to be continued next week.

The other big exercise was the continuation of work with a large B&G team to relocate the materials from West of the shop access road. 

The tricky items such as the tank and cab of the 0-4-0 were safely located to a much better area, where they are now standing on more secure supports that will keep them clear of the ground.

You could not even stand here last week !

So we will be back next Saturday with the target of making a good deal more progress with the riveting.

Nigel