Steam Department Update 10-20-2012

This was a productive day in the steam shop but may sound rather dull from the blog perspective.  In essence successful progress toward having 1630 running next year will depend upon doing the same repetitive tasks for much of the next month or two.

The question is often asked - will 1630 be running next year?.  The answer is that we sure hope that it will and are doing our best to ensure that it does.  One thing that will have a major effect is funding.  While we have the major materials in hand, we are now pretty much out of funds on both 1630 and 428.  There will be steps where we can save time by having some work done by specialists but we currently do not have that option.  So .................. please consider donations to the 1630 or 428 funds. 

The next major milestone is to have the boiler water tight again.  To do this we must refit about 180 fire tubes plus 16 super heater flues and fit the patch in the firebox.  Once the boiler is proved water tight we can move on the last leg which is to refit super heater elements, accessories and lagging before carrying out the hydrostatic and steam tests that will prove fitness to run.

Fitting each tube has several steps

·         the tube is first swaged, which means reducing the diameter of the 2 inch tube to 1 7/8th at the end which will be fitted into the rear tube sheet.  This is done by heating and then hammering in the dies of the swaging machine.

·         the tube is then cut accurately to a length that will allow 1/4 inch projection at the rear tube sheet and 1/4 to 3/8th at the front.  Since there is a variation of close to 1/2 inch between the longest and shortest tune, this requires matching of tubes to specific locations.

·         copper ferrules are then expanded into the holes in the rear tube sheet to make a better seal between the tube and the tube sheet.

·         tubes are then placed into position and the process of fitting can begin.  The fitting is itself a multistage process consisting of:

o   expanding the tube, using a set of rollers, so that it is a tight fit into the tube sheet;

o   rolling over the projecting end of all the tubes in the fire box and some in the smoke box

o   further expanding the tube just behind the tube sheet to provide a second level of sealing.

Each step will not be completed for all tubes in sequence as, for example, we do not have sufficient space to have 180 17 foot tubes in the shop.  So some will need to be located in the boiler before we can swage more.

Thanks to Eric Olson for the photographs below, which show the swaging operation.  Shots of this operation were hard to come by as I am busy playing with a red hot tube rather than a camera!!.

Step 1 - the end of the tube is heated in the oil fired furnace:

Heat the tube end

Step 2 - a wire brush is used to remove mill scale from the surface of the tube which the hammer might drive into the metal causing surface damage:

Clean the tube end

Step 3 - the tube is briefly re-heated, then the end is placed into the swaging hammer.  The tube must be turned steadily while the hammer is working to get a smooth surface and even reduction in diameter.  One of the learnings is that, while I have loaded the tube and am operating the swager, Jeff is turning the tube.  The tube is so darned hot where I am that you cannot grip it to turn smoothly even with heat resisting gloves.

Into the swager

Step 4 - The tube then joins the stack of swaged tubes to cool while we move on to the next one:

One more tube swaged

This week, within this overall process:

·         we completed marking the tube sheets so that we can now clearly see which length of tube is required for each hole and into which hole in the rear tube sheet the tube must run from each hole in the front tube sheet.

·         after encountering a few problems with the swaging machine, we established a good "production" process and swaged a further 20 tubes so we are now up to about 45 swaged.

·         calculated the length of tube required to correspond to the measured lengths between tube sheets and cut the first of the standard lengths.  The game plan will be to ensure thru test fitting that a standard tube of each length correctly fits a sample of the holes in the tube sheets for that length and then use these as a pattern from which to start "mass producing" tubes of each required length.

·         in addition to the work on the tubes, the patch for the firebox was bent on the McCabe and, when I left, there were some fairly positive mutterings coming from inside the firebox where Mike was offering it up to its location.  Having the patch accurately formed to the mud ring will be a big step forward on that activity.  This provided an interesting demonstration of the power of the McCabe flanger. 

This is 1/2 inch thick steel boiler plate.  The flat section of plate is clamped into the jaws:

Plate loaded and clamped

As air is applied to the main cylinder the jaws move down and bend the plate.  The startling thing when operating the machine is that there is no noticeable change in tone or speed of movement as it contacts the plate.  You have to watch carefully to see when you start the bend as the machine shows no load at all when bending this thick plate.

Bending in progress

... and in very little time you have the full right angle bend.

Patch bent to shape

In other areas:

·         Ed and Bob further cleaned the valve block for the planer after a week in the cleaning tank.  The flow of "black goo" now seems to have ceased and the internal passages look pretty clean.  So hopefully that is now getting close to the point where it can be reassembled and refitted.

·         The "new" air reservoir was moved to the South end of the shop to set up for hydro testing.  This raised some interesting questions about what sort of air filter was in place when it was used by the Milwaukee Road.  Jerry removed the most incredible amount of debris from the bottom of the tank which seemed to consist of general dirt and dust held into substantial blocks by compressor oil !.

So a productive weekend in the steam shop.

Nigel