I've just put up a series of photos showing how the boiler jacket on CNR 6213 in Toronto, Ontario is supported since its asbestos lagging was removed in 1985. This method has worked extremely well over the past 26 years and the jacket is still in excellent condition.

I think this should serve as the primary model for those intending to replace the boiler jacket on a park engine.

http://www.trainweb.org/j.dimech/6167/6213bj.html

The total cost of this refurbishment was $600,000 paid for by the City of Toronto. As the work neared the end money for summer student project ran out and the work had to be finished by volunteers. It wasn't all that bad looking as it had been protected by a sturdy steel fence and cared for by UCRS member/volunteers. Certainly near the top of park engines.

The Frisco used a novel method to space out the jacketing when they donated a locomotive. They removed all the lagging, then tack welded pieces of stainless about 3" square around the circumference of th boiler, like little spines sticking out. Then they took a long strip of 3" wide SS and wrapped it around on the spines and tacked it to them. They did this about every 18-24" along the length of the boiler. Then they made new jacketing out of galvanized sheet metal and prepped it for painting after installation. They put a lot of work into restoring their engines for display. The only one I know of that they didn't restore was the 4502 that went to Dallas for some reason.

Sigh, if only every other railroad that donated equipment was so conscientious...

How were the foam strips held on? Were they glued? Also, how were the ceder strips held on before the plastic bands were put on, or were the applied at the same time?

-Alex

I've seen several mentions of using cedar or treated pine blocks for spacing jacketing in place of the lagging, but I want to point out that while these materials won't rot quickly, they still retain water and hold it against the steel, so don't protect the boiler shell. I think we have to assume that any jacket will eventually leak, and when it does so, the ideal situation would be to have the water take the quickest route to drain holes in the bottom of the jacket. Anything that holds water against the steel should be avoided. I am very afraid that one of these engines will be stripped in the future, only to show rectangles of severe pitting at places where the wood was in contact with the boiler shell.

I think the jury is still out on Styrofoam blocks; the closed cell foam used for below grade applications (the pink or blue stuff) won't absorb water, but will still hold water against the steel by capillary action.

One of the most innovative materials I've seen used is plastic pipe; plain old PVC sch. 40 DWV pipe available from the big box home centers. Attached by tying it to stainless steel wire the same way the original magnesia blocks were, the wire wrap also serves to space it slightly away from the boiler shell. Even if it does lay on the shell, the contact area is minimal. The only problem would be if leaves or other organic materials (like mouse nests) get carried or washed into the space between the jacket and the boiler shell; the pipes will keep them from washing out.

I've often thought that the ideal spacer material would be welded wire re-bar bolsters:

http://www.rebarplastics.com/product/SB

They can be had with different length legs to match whatever the lagging thickness was. They can be had galvanized, with plastic tips that will keep them from rubbing through the paint on the boiler shell as they move due to thermal expansion. They should also be easy to tie to stainless steel wires to keep them spaced while the jacketing is applied.

Well, we'll find out the results of this "experiment" if and when 6213's jacket ever comes off.

alcoguy1: I passed on your question, and this is the answer I was given:

Foam strips on sides of firebox fastened either by glue or by nails driven into staybolts, as required. Upper pieces, where practical, sandwiched between staybolt caps or other fittings. NOTE: Regarding glue/adhesives: make sure they are compatible with the foam and use sparingly.

Cedar strips: Run plastic strapping under and around boiler with ends up at sides as if boiler was going to be lifted like a cradle. Strap can actually be loosely rolled right around boiler shell and cut with excess material to allow slightly more than sufficient space for installation of cedar strips. Ends will be at the top and can either be temporarily fastened together, or have people hold the ends. Note that as the cedar strips are applied, the weight on the straps will increase. You will most likely need three or four straps per boiler course. Co-ordination on each strap will be required. Slip cedar strips in between boiler shell and straps starting at bottom. Try to go left, right, left right, etc. working your way up the sides evenly. As each strip is put in place (left and right) pull strap taut (to pull strip into boiler shell) and fasten strap to strip with stainless steel staple. Once you are above the half-way point (generally above the running board), the process becomes a little easier due to accessibility. When the last strips are applied at the top, the ends of the straps can be stapled to several strips over on the opposite side. NOTES: Plastic strapping is typically the type used to palletize boxes. It's not actually that bad holding the weight of the strips on the lower portion as you do not need as many down there as compared to the upper half. As a result, it is also not as time consuming as you might think - especially due to the cramped working quarters under the boiler between the frame. It will obviously be necessary to simultaneously rig a strap at (or near) each end of the boiler course as a minimum and this method will hold the strips in place. As mentioned above, further straps (as many as thought to be required) can be installed for extra security. And they can be placed wherever is most convenient given the landscape of the boiler shell. There are no steadfast rules or procedures for installation. While the method sounds simple, care and thought must be made in advance given the many and varied nuances of every boiler. Plan to have lots of people on site to lend as many hands as may be required. And plan to use good old fashioned ingenuity. Above all, work safe and have fun.