Steam Department Update 09-07-2013

·         On Saturday teams of us took it in turns to prosser the tube ends in the rear tube sheet.  This process involves expanding the tube slightly on the water side of the tube sheet, using a multi-segment expander driven by an air hammer.  The effect of slightly expanding the tube on the water side is to firmly lock the tube into the sheet between the bead and the slight expansion caused by prossering.  Anyway, it is a two man job and, by several teams taking it in turns, all 200 tubes were completed by late afternoon.  The boiler was then refilled and we started to heat the water.  The objective on Sunday will be to test the tube ends under operating pressure and tighten any that show leaks as a result of the beading and prossering.  As soon as we are satisfied that the tube ends are dry, the tubing exercise is complete.  The motor can then be removed from the smoke box and installation of the super heater elements can begin.  So I wait with some trepidation to see if this can be achieved on Sunday !.

·         Stu and Bob worked with Tom to set up a mounting that will allow the throttle to be rigidly located for machining and lapping.  The surfaces of the throttle valve need to be leveled and ground to a tight fit that will provide a good seal before the throttle is refitted.  By end of day the throttle was mounted and ready for work to be done.

·         Dennis started on the plate work and mesh that fits around the blast pipe.  He has now assessed all the pieces and identified what new material will need to be fitted to complete this structure once the blast pipe is in place and the super heater elements tested.

·         The lagging is proving rather more troublesome. Two areas are critical for the steam test, the firebox in the cab (to allow fitting of numerous pipes, valves and gauges that are required both for steam testing and pressure testing of the super heater elements) and the first couple of sections of the barrel at the front (to allow refitting of the large air tanks required to complete the air system).

·         Work started on fitting the barrel lagging at the front.  This is not as simple as it looks (and it does not even look that simple !).  The insulation is rigid blocks that cannot be conformed to the curvature of the barrel.  So it must be cut into strips about 12 inches wide and the edges cut at an angle so that adjacent blocks fit tightly together along their length.  However the blocks must also be tapered along their length.  The boiler is formed of 3/4 inch plate in overlapping sections.  So, in order to get a smooth taper over which the sheet metal can be fitted, the 2 1/2 inch insulation must be tapered along its length.  (Basically the last section at the rear of one boiler ring is the full 2 1/2 inches thick while the front section on the next ring to the rear is 1 3/4 inches thick so that the insulation runs smoothly over the 3/4 inch transition in the boiler plates).  Then, having cut sections of insulation to the correct taper along its length and sides, each must be cut around any pipes, hand rails or other projections to fit a specific location.  The block is then wired to the wire rings that were placed around the barrel some weeks ago until a complete circle is achieved around the boiler.  This will then be strapped into place and the sheet metal fitted over it.

Eric fits blocks of lagging

The circle begins to form

·         The sheet metal provided a bit of a setback.  Jane had done a lot of work to ensure that all the metal had been cleaned and primed  ready for use and had actually been short of painting work in the last couple of weeks once this was done.  When we tried to locate the first major sheets required for the front ring they could not be found .............. until we found a whole lot of 1630 sheet metal that had been stored behind a few sheets belonging to #26 !!.  It had been overlooked for cleaning and painting so Jerry spent much of the evening wire brushing a lot of sheets and I started painting the ones we need most urgently ..... oh bleep !.

Jerry hard at work on the ones we overlooked

·         However the real nightmare is the cab.  The sheets covering the top and sides of the firebox in the cab overlap and hold down the curved sections that cover the transition between wrapper and backhead.  These, in turn, secure the sheets covering the backhead.  The arch of sheet metal running up the sides and across the top of the firebox in the cab must first be located so that the curved sections can be located under its edge.  The critical element of the arch is that two pieces of sheet metal must be worked up into the maze of pipes and valves around the turret and linked with 3/8th threaded rods either side of the turret. In addition, insulation must be set under this area in the form of small cut blocks or mud.  Once the link is made the sheets form a complete arch that is tensioned by other threaded rods secured into the footplate.  All jolly good fun as the area into which the metal and insulation must be placed can only be reached at arms' length from the narrow space at the sides of the firebox or by lying on the cab roof and reaching down several feet into a nest of pipes.

o   Most of the work in this area on Saturday was planning to determine in which order pieces can best be fitted.  This is critical to the project as the controls essential to testing for leakage in the super heaters cannot be fitted until this is done.

o   The sheet metal either side of the firebox is in place to provide protection to the insulation already installed.

Sheet metal in place in the cab

o   David finished cleaning the fire hole door and I chased the threads on the mounting studs so this can be fitted as soon as the tube ends in the fire box have been proved tight.  This is important as much of the backhead lagging is based upon the fire hole door casting.

In other areas within the shop:

·         Phil and Cameron worked with Tom on machining the bolster for the Shay;

·         Dennis started the long process of building up the axle boxes for 428;

First steps in building up the axle boxes

·         Stu and Bob achieved a major milestone on the planer.  The power is now connected and both motors were tested.  The head can now be raised and lowered correctly and the motor driving the hydraulic pump now operates.  The next big challenge is how to remove decades of muck from the drain area under the bed.  Since the lubricant supply to the table is collected and returned to the pump thru this area, there is a considerable incentive to get it as clean as possible before we try circulating oil thru the system.

The planer is now starting to work

So, a lot of work done but still a good deal more needed to get to the steam test.

Nigel