Steam Department Update 5-12-2012

Generally a successful and productive day in the shop.

The best news is that Tom was sufficiently recovered to be back at the shop.

A lot was progressed on 1630:

·         There was a change to the plans for the thickness testing as Ralph's brother will not be able to come back to complete this for several weeks.  However, this is not necessarily an overall delay as we already have enough information to start reviewing the calculations for the form 4 (engineering analysis of the boiler) with Bob Hunter, who will prepare it;

·         We did an initial review with Bob, who is now working with the previous form 4 data to determine what operating pressure we should consider.  I now have a bunch of "homework" to plot all the measurements on diagrams of the sheets.  One benefit of the second set of measurements being later is that we can review these with Bob and decide if we need any additional data points on the main sheets before Tom next comes;

·         All the remaining sections of the boiler are now marked up with points for testing aside from the dome top.  In view of the successful sand blasting set up noted below, it was decided that this part would benefit from sandblasting before we test it;

Dome cover before sand blasting

                Hopefully we will have an "after" view soon !!

·         Collin  and Jeff did close examination of the back head braces using a boroscope.  These braces are of particular interest as it was calculation of the loads on these that resulted in the reduced operating pressure from 2001.  They are very inaccessible (running from the top of the wrapper to the back head above the inner firebox and among a forest of crown stays).  The conclusion is that their condition is excellent.  The camera shows no sign of wastage and, where we can get to them with a micrometer, they are still pretty much at the size shown when the boiler was built in 1917.  So, if the conclusion is that these are not considered sufficient for 180 psi operation, it will be due to requirement for a greater safety margin than historically required rather than any wear or damage;

The mounting of a back head brace among the crown stays

·         Jeff and I worked on the firebox stays.  All the stays must be proved to be sound either by demonstrating that a tell tale hole is clear thru to the head of the stay or by removing the cap and hammer testing.  Most have tell tales that we have ensured are clear but a number are solid so must be hammer tested.  This was a job approached with considerable concern as the caps look very rusted and, should they break as you try to remove the caps, the stay must be replaced.  Each replacement would be a substantial job.  Much to my surprise this task proved not to be as bad as feared.  Having identified the outer ends of the stays to be examined we started heating each one and then tried to remove the cap with a wrench.   To our great surprise, once heated, each cap unscrewed smoothly from its socket.  The rusting is far more superficial that appearance suggests and, once heated and the cap removed, the stay head looks relatively clean.  Building on our success in removing the required 9 caps on the engineer's side wrapper we tried some on the back head.  While these do have good tell tales we were concerned from appearance that the sockets were so rusted as to require replacement.  Again the experience was not only that the caps removed without issue but that the sockets are actually much thicker than they appear so few if any require replacement.  Altogether a lot of potential work avoided.

Flexi stay caps

The three lower stays, now with the caps released, looked like the row above earlier in the day.  Amazing how much of the apparent rust damage is actually superficial.

Elsewhere Stu, Matt and Glenn fitted the new cast face to the small rivet furnace.  This is now ready to cast the fire brick interior.  Once this is complete we can hopefully complete the cab for 428.

Stu and Matt prepare the new casting

The furnace case is now complete

Bob has de-winterized the water supply ready for Leviathan, which is expected next weekend.

Jeff and Phil set up for sand blasting parts outside using material recovered from the boiler cleaning.  After a few issues with screening the used material, the process was established and proved using the hood of the Bay City.  Now it is proved we can set up quickly and next week should be able to work on parts of 1630 and 428.

Paul and Bob continued on the Shay truck.  One small but time consuming job is caused by the fact that a number of the raised metal washers that stop the springs moving are missing.  In this view you can see what should be two rows of 5 spring retainers.  The wear around each shows where the spring resting against the bolster carried the weight of the locomotive.  You can see in  this view two washers missing leaving just a broken pin.

Spring retainers on top bolster

These prove to be held in place by rivets driven into a blind hole.  This is no great problem where the rivet has pulled out but "great fun" where the rivet has sheared off and must be carefully drilled and then removed in pieces to make the recess into which a new rivet can be driven. 

One that was removed, as it was loose, shows the way in which the rivet expands into a groove to hold the assembly into place.

Construction of the spring retainer

Significant progress was made on the bull rings for 428 where Mike was finalizing the machining of the third ring while Tom and Ralph were starting the fourth and last one.

Starting work on the last bull ring

Nigel