Steam & Excursion > B&M 3713

Anyone know how far along in the restoration process is this project? Pics would be nice.

Well.... You KNOW what HotWater would say....

Id suspect that they're at a crucial stage in progress and now
need a SUBSTANTIAL infusion of cash.

When outfits go 'radio-silent' , it generally means a stalled project.
it Costs Money to complete a boiler initial certification & ultrasound 
measurements.   The ultrasound measurements are readings taken of 
the boiler shell sheet-thickness.

The interior boile inspection and ultrasound numbers are used to locate
the 'thin-est' areas of the shell structure.  Those numbers are then
used to calculate the 4:1 design requirement for allowable 
maximum boiler pressure.  

A boiler intended for 250PSI operating pressure must be constructed
to meet the 4:1 safety margin.  4 X 250 = 1000psi design pressure.
Mechanical engineers must certify their fresh calculations, and like
in school 'show your work'..

With possible eroded and thinner shell readings,  that would produce
lower allowable operating pressures.

The "fresh" calculations are the intent of the safety rules.
Such procedures have been recently requested on other areas of the
boioer---+such as soot checking boiler fkues and tubes...
In my opinion, such additional testing is superfluous, and applying 
uktrasound readings of boiler tubes is not tge rewuirement.

But, if the FRA insoectir requests it, the pridunt course is to comply.
But, IMHO, ulrasound readings of areas other than the boiler-shell, proper,
are superfluous.. 

Design pressure has no relevancy to hydrostatic test pressures.
Boiler hydrostatic test pressure is 125% of the boiler's intended 
operating pressure.   

The benefit of the hydrostatic pressure is that it will stretch the furebixstsy bolts ---
openining up any cracks or tears that reach the center drilled, tell-tale 
weep holes.  Stay bolts that had been threaded for installation,
typically will tear in regions near the water-side of the staybolts.

Current practice now is to prepare the staybolt holes for
stays that are welded-in place in the firebox sheets.  
That has two benefits:  the bolts are not weakened by threads 
cut into the bolt diameters, and the weld-bead forms a uniform
thermally-conductive joint.  The firebox sheets are typically 
3/8" thick, and staybolts are typically 1" in diameter...

When heated, the two thicknesses behave differently account
of different thicknesses.  There is always a boundary between the
two different-thickness structures ---- suseceptible to leaking.

Welding forms a uniform, thermally conductive structure that ensures
stronger joints, than old-style threaded fastening.

Staybolts that are drilled, can tear into the tell-tale holes, and
hydrostatic pressures will open-up any cracks --- and allow 
water leakage.  Non-drilled staybolt must be hammer-tested
while under hydrostatic pressure.

In the old days, it was common for boilermakers to 
climb into hot  fireboxes ( with cleaned-off grates) and hammer
test all the stays, while there is still pressure on the boiler.

Retained boiler pressure keeps all the stays tightly stretched,
and hammer blows ( sharp raps) rebound from the solid stays.
A defect on the bolt will absorb the 'shock wave', and the
hammer head will NOT be kicked-back.  The hammer will
'stick' to the defective bolt, as if magnetized.

As you can imagine, a hard blow will produce ambiguous 
reaction, ---- so, the boilermaker's blows are a sharp, quick 
rap, NOT a strong, driving blow; and, he gets into a rapid-rhythm
as he tests the rows of staybolts.

Long-length crown bolts rarely fail, their greater length makes
them more flexible, and not liable to fail.

Muscle-memory plays a vital role in the field of boilermaking
skills.   It takes years of working & testing to become good at it.
I salute the young guys that I've seen, as they train to be
tomorrow's Boilermakers.

Its one advantage to complying with the FRA boiler inspection 
requirements --- it makes repetitive, "educational" requirements
a part of continued, safe pressure operation of loco boilers.

​W.


 



Edited 1 time(s). Last edit at 06/02/23 07:45 by wcamp1472.

I recently visited Steamtown and was given a good briefing on the 3713. They have done high quality work on her and are ready to finish reassembling the tender ( all the parts are there and ready ) and they are ready to finish the boiler work as well. What's needed now is a fresh infusion of cash. Scranton has repeatedly requested funds to finish the engine and so far has been turned down. They intend to keep trying. 

   Ross Rowland 

Thanks Ross.   Scranton has repeatedly requested funds .  Does Scranton = Steamtown NP?   Who did they request funds from?  US Treasury???

If I hit a big Powerball could I as an individual make it happen?    

Yes, the SNHS has requested suplimental additional funding for several years to be devoted to finishing the 3713 and so far those requests have been denied. They'll keep trying.

   She'll be one fine horse when she's done. 

   IMHO-Ross Rowland