Illinois Railway Museum Blog

A lot of work, a good deal of progress and some frustration.  That is probably a good summary of the week in the steam shop.  While a few of the team were able to assist with Thomas, most of us were hard at work in the shop.

Everything is focused on getting the hydro test for 1630 completed.

Tom, Mike and a small team worked long hours on Wednesday to get the two stays installed.  They were in place ready for the Saturday team.  Brian Davis and Jason, inside the firebox, worked with Brian and Sean, on the bucker in the cab, to hammer over the ends inside the firebox to compete the installation.  This was a rotten job as the stays are high up above the arch tubes on the back sheet of the firebox.  This makes it a very awkward place to operate the air hammer.  However, they did it and the stays proved leak free in all the subsequent testing.

Life was no easier for the team in the firebox because we need to have the water in the boiler heated to 100 - 105 F and this takes a while for the pool heater to achieve.  So, while they worked in the box, we had increasingly warm water circulating around it (not up to the level of the two stays but well up the sides of the box).  So, by working inside a hot water radiator we were able to ensure that none of us who worked on the firebox tube ends during the day were in any danger of suffering from the cold on an 80 degree day !!.

By lunchtime we were able to apply pressure to the boiler.  The more significant leaks from three weeks ago were corrected so there was now no problem with getting to the full pressure required for the hydro (1.25 times operating pressure so 225 psi).  Various leaks were found and corrected.  This is an iterative process, test, identify, tighten and retest.  At one stage on Saturday we did think that we might be able to do the formal hydro on Sunday.  However tiny leaks around tube ends proved frustratingly difficult to close.  This is one of the joys of working with a steam locomotive boiler.  Since the tube sheet consists of many holes close together, the force of expanding one tube can easily cause a minor movement to the next tube so you can spend a good deal of time chasing tiny leaks from one tube to the next before you get everything tight.  I went back on Sunday morning to work with Brian, who is staying at Union for 3 weeks or so, and we still further reduced the number of leaking tube ends.  However, it will be a continuing process during the week and probably into next weekend to get all the tube ends completely tight.

The pictures look extremely dull but are all the better for that.  The tiny leaks can be seen around tube ends in the smokebox.

Brian checks the tube sheet and marks any issues

The overall rate of leakage is very gratifying.  This small area is now the most significant group of tube ends to be tightened.  You have to look closely in the center to see the small seepage that we must stop. 

A small group of tubes to be tightened

The real achievement is not apparent at the smokebox end.  The sheet and tubes are actually under 225 psi pressure when you look at the gauge in the cab!!. 

The one indication that something is different

The new stays are leak free at 225 psi.

The stays in place and under pressure

The pressure drops from 225 at barely 1 psi per minute, an indication that the leaks are tiny in volume.  However, where they are in areas like the tube ends, they must be completely corrected.  So a week of frustrating work, tightening groups of tube ends and then checking the results with another pressure test lies ahead.  If we get too frustrated, it is good to think back to the fact that, not long ago, the boiler was wide open.  Now we can routinely plan to leave it totally full with minimal leakage for days on end.

The one unexpected item discovered was the union nut at the bottom of the fireman's gauge glass.  Tiny droplets of water appearing thru what should be solid brass were an indication of hairline cracking.  Tom now had quite a few hours of work to produce a replacement for the hydro test but I understand that this was fitted on Sunday afternoon.

Updates from Brian so far indicate that most of the leaks have been corrected by Tuesday so we hope that we can move on to other work next weekend around the planned hydro test on Sunday.

Nigel