crown sheet question

B

bendorsey

Bridge-n-trestle builder
I was looking in one of the RR books I have and happened to re-read a section that said the crown sheet in the Uintah 3 ft ga 2-6-6-2T was inclined 7.5 degrees to compensate for the roads 7.5 degree grades (7.5 degrees is not a typo). That might make sense in one direction since it helps prevent the top of the crown sheet from becoming uncovered by water but what happens when it goes the other way? Crown sheet would be off by 15 degrees. Not good (think kaboom, lol). Any ideas gents? I know darn well they don't swivel.

Ben
 
Personally I wouldn't worry about the crown sheet, once you get rolling down a grade that steep you could pretty much close the throttle and douse the fire, gravity will get you to the bottom. Question is, how do they keep the brakes from melting? :eek:
 
The crown sheet should be fine, the water is probably sloshing all over the back head anyway. What I would be concerned about is the fusible plugs. If the fire is too hot on them, or they don't have enough water over top, they would melt, causeing the steam to shoot into the firebox, and damanging the whole firebox crown and all; preventing an explosion.

Rock On!
~Dusten
 
They didn't run them backwards: in fact they had their backup lights removed, which generally means you aren't going to run backwards. Maybe I'm wrong (more like probably:hehe:) but i think the rules say you need to have a light on both ends if the engine is going to run tender (or bunker) first.

anyway, there was a second steam dome added to No. 50 after she was delivered, and 51 as she was being built. one engineer quit the Uintah and went to a flatlands railway because he was afraid the mallets were going to blow up...more than once he reported that the water sight glass would drain completely going down the Atchee side of Baxter pass; that's the side with the 7.5 percent grade. Personally, if i saw that, I wouldn't bother quitting, i'd just jump out the cab window.
 
It's all downhill from here!

Again, why not just damp down the fire? You don't need any steam to fall off a cliff. :hehe:
 
you would still need steam to power the air pumps, and a locomotive on a railway that steep would most likely have a steam brake, which injects steam into the pistons opposite the direction of travel; IE if the piston is moving forward, you put steam in the chamber to the front of the piston. It's actually a lot more complicated than that, but that's the general jist.
 
I gotta agreee with you sawyer811 - jump off and run like the hounds of hell are chasing you, lol.

Heres another question:

After they were sold to the Sumpter Valley RR and converted to tender engines did they level out the crown sheets? The SVRR certainly had grades but I seriously doubt they were anywhere near those on the Uintah. In fact the only photo I've ever seen of one of the SV conversions is number 251 on page 188 of Narrow Gauge in the Rockies by Beebe & Clegg and its on flat ground pulling quite a long train.

Now if we could only convince the gent that made the Uintah 2-6-6-2T to make the SV version as well (we all have dreams - this is mine).

Ben
 
If the water glasses are 3" above crown like they're supposed to be, then it should be no problem. If water level is maintained right (on the road, 3/4 glass going upgrade, half on level, and water visible going down), the crown would be covered at all times. Maintaining water going uphill is harder than maintaining going down, as the highest point of the crown is toward the front which means even if water is in the glass it might not be covered (this is why the 1218 never went up Saluda, they calculated that to go up, the water level would have to be 5" above the backhead at a minimum). Going downgrade the water is always above the crown because the highest point of crown is toward the backhead, so if water is in glasses, you're good.
 
You must log in or register to reply here.
Back
Top