After 106 years engine No. 98's blast pipe has reached the end of the line. The original was cast. Making a pattern and casting a new one is very costly so we chose to fabricate a new one. The new one is beefy enough that it should last another 106 years.

What exactly does a blast pipe do? Does it have something to do with forcing the exhaust out the smoke stake?

...adding to your answer - aiding in drafting..

Tom, nice work... who did the welding?....S Jr.?

Don't you hate it when things just wear out? :-)

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Kelly would you care to elaborate on that idea a bit? I would be very curious to the construction of this "splitter", especially if it can work with a 3 cylinder locomotive!

Yes, there is a splitter in the middle. It is of the same dimension as what the folks at American Locomotive Co. installed in 1909. I didn't do any of this work. Our hard-working and talented CMO coaxed all of the steam pipes out of the front end without breaking anything and a local boilermaker has done the fab work at a very reasonable cost.

I am looking at fabricating a new blast pipe for the J&L 58. It is much shorter in height, but displays the same erosion and corrosion that the 98's old pipe has.

My approach is going to be a bit different. The new blast pipe will be a series of 1 1/4" burnouts stacked on top of each other, with the interior passages milled to the correct taper on each burnout. The stack of burnouts will then be welded together forming the new blast pipe. I looked at fabricating the new one similar to the way 98's pipe is made, but its so small that I would be trying to piece together a lot of very small pieces and its not easy welding on the interior of such a small space. I haven't yet ordered the burnouts as we are several months away from needing the blast pipe, but its all drawn up in CAD and ready to go.

Here are a couple more of the finished product. The TEE in the steam delivery pipe is being fabricated next. More to follow.

I'm not sure what, but would the weld bead inside have any effect?
1522 always had sort of a "chirp" when running with a light exhaust. We never did figure out what caused it unless it was a cavity in the exhaust passages in the cylinders.

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Paging Dr Koopmans and Hugh Odom.......

Yeah, thanks! This situation was tested by Prof.Goss who reported on it. A summary can be found in his book "Locomotive Performance" which can be found reproduced in full on the web. See page 220 (in my version of 1907), might differ slightly depending on the version found.
Kind regards
Jos Koopmans

The original publication of Goss was in Master Mechanics Proceedings 1896" Report on Exhaust pipes and Steam Passages" p.58-143.
In it he shows Plate 14 with the results of a test in which the bridge was diminished from 12 to 4 inches in height. This is the only test with a single(?) variable, in a number of cases the height of the blast pipe was diminished together with the bridge. In this case the blast pipe changes slightly with the height of the bridge.
Results: all tests steam pressure 16.7 psi. Vacuum 3-3.05 in. of water. Back pressure
starts with 1.25 psi for the 12 in bridge, the 1.3( 10), 1.35 (8), 1.3 (6) and finally 1.4 for the 4 in. bridge.
IMHO this is all counterintuitive. A larger bridge gives more wall area leading to more backpressure but apparently not. Also longer coflowing without a bridge would accelerate
the slower stream, which could lead to suction from that slower stream. However, since the smallest bridge gives the highest backpressure this is not so.
Kind regards
Jos Koopmans

Can't lay hands on my red Devil right now, but I think this was something known as a Kordina...... Seems mysterious to me and I'd like to know more.

Tom, that's very good work. Thanks.