Pennsylvania RR Duplex 4-4-4-4 replica build

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Perhaps it was simply a matter of it not being worth redesigning and making new connecting and side rods. Other large American engines had the same or similar Timken lightweight rods and roller bearings on the rods. N&W J class for example
had them and 300 psi. You could look up the operating pressure on any of the later engines who used roller rods. And dont forget, engines did not run at full pressure all the time.

 

I'd imagine such forces impacted heavily on chassis design and therefore weight. Presumably the adoption of cast steel frames, as applied in some later designs, allowed arrangements not readily achievable with the earlier bar frames.

 

The third section of the boiler barrel now constructed!
https://www.facebook.com/t1locomoti...1828.591467160889599/1734561703246800/?type=3

Knut

 

? The original only had two circular barrel sections (if you don't include the smokebox). Modest little firebox with circulators and combustion chamber.

 

Well, depending on how you look on it, the section around the combustion chamber is a "circular barrel" as well. Albeit with lots of stays.

 

This current picture from the T1 Thrust facebook page clearly shows the size of this boiler!

https://scontent-arn2-1.xx.fbcdn.ne...=02f57717d7b9f3ebf28c289bd70a9b15&oe=5BE510DF

Knut

 

CAD drawing of PPR T1 frame

from T1 Trust facebook page

https://www.facebook.com/t1locomoti...1828.591467160889599/1809667019069601/?type=3

Knut

 

Have a look at this AMAZING new video promoting this new build project!



Knut

 

Firebox construction video....

 

Thank you som much for posting this Johann! Look at the size of the firebox!
Seems like a job for guys with good physique this one.

Knut

 

Another video update...

 

Good lord! Continental Fabricators are well-named, they could probably knock out a quick Africa if they can do that boiler...

Also, the tubeplate looks like lace, not a lot of gap between those tubes.

They look to have built the boiler first. How does the US system re boiler certs work compared to the UK system?

 

What triggers the start of the 15 years? presumably they won't do that bit until they have build a lot more of it. (AIUI UK new builds tend to do the boiler last for that reason - when it's finished it's ten-year interval starts counting down)

 

Or 1472 service days AFAIK. (i.e. 15 years or 1472 days - whichever is less).

Tom

 

If I remember it correctly from a discussion on UP 4014, the counter starts ticking only when the boiler starts to produce steam the first time.
Thus it could be pressure tested with warm water prior to that.

 

The Corris did No.10's boiler first. AIUI, because the feeling was it's about as firm a statement you're serious as it's possible to make. Isn't the steam test when the clock starts ticking?

I tripped over a still of the T1 boiler, as shown in Johann's post, [#32]. Ye gods, that thing is absolutely humongous.

I'm still having to pinch myself to believe progress is coming on this fast. You have to imagine Cheyenne's well publicised return of 4014 (take a well earned bow, UP management and restoration team!) has generated a fair bit of interest in US steam and the iconic T1 is just the right project at just the right time.

What if they're serious about going for Mallard's record? If there's one design with a realistic chance, it's surely this one. Couple that with all the renewed interest in US high speed rail (What? You hadn't heard the rumblings?), it's a possibility which suddenly doesn't seem quite as far fetched. What a great way that'd be to hand the baton over to modern high speed OHLE in a blaze of publicity that'd be seen right around the world.

 

They could ask Jeff Bezos to pay for this loco from his small change, with the completed loco being named 'Amazon '

Bob.

 

One of the problems with the original T1s was damage caused to the poppet valves, a problem that was never completely resolved. This was thought to be over-speeding outside the design parameters. That over-speeding was almost certainly caused by speeds in excess of 130mph, although there is no recognised, accurate and authenticated record of such speeds. If the new build is given it's head, Mallard's record may well go across the water.