I read an account of a roundhouse tour during the steam-diesel transition period where a steam locomotive was described as “sitting on house steam”. I took this to mean that the boiler was being kept warm by steam from the roundhouse power plant so it could be brought into service in a shorter time. Is this correct?
… and if so, how is it done… what would you connect the house steam line to?
Yes. Appliances on the steamers had to be inspected and tested, and that required steam in most cases. So, once in the bay, the engines would eventually be hooked up to house steam for that purpose, and also to keep the boiler from cooling unduly and possibly having things crack or break. Thermal cycling is bad, as the engineers had known for decades by then.
I’m sure someone will add or correct me if I’m wrong, but house steam was introduced by plugging the boiler piping into the steam system that heated the roundhouse via a coupling. The steam preheated the boiler tubing and allowed the engine to make steam faster when fired up. Most home steam systems make little or no pressure (my home furnace makes +/- 5psi) so I’m pretty sure this would have simply have avoided making the fire have to heat up the entire boiler and tube system which takes quite a long time (hours) after it’s all “cold soaked”. J.R.
I’ve heard it said a number of times that this is a particular problem for excursion steam engines, because they are not kept at operating temperature as they were during their years of normal service, and the continual cycling between cold and hot fatigues the steel at a faster rate.
NKP 765 is undergoing a new total overhaul, I think the more risky areas are the flues and their connections. Prolly the superheaters closer to the firebox end, my experience from its 1st overhaul in the 70s, the superheaters were more rusted on that end, maybe with holes.
Well, the engines go thru a periodic servicing anyways on the prototype when they were active anyways, so wear and tear still happens.
House steam was generated by a stationary boiler in the boiler room and was fairly high in pressure. The house steam was coupled to the engine boiler and did preheat the water slowly and give the locomotive a sufficient amount of presure to leave the roundhouse. The house steam presure was used after a locomotive was cooled, drained if necessary and repaires made to staybolts or other boiler functions like boiler washes. After the repairs or wash outs, the house steam was connected to warm the water back up to temperature slowly and the engine could be run outside on house steam and if fired on oil, the fire would be ignited outside.
House steam was used also to keep locomotives hot if they were not needed daily and the engine would be warm under a lower than normal working steam presure. They could be fired in less than an hour if needed and placed on the ready track since they were hot and serviced and only needed the fire placed back into the firebox.
I watched the 8444 back in the seventies several different times at Cheyenne on house steam move out to the turntable and to the ready tracks prior to the Oil fire being lit.
Cheers
The Nickel Plate 765 WAS JUST rebuilt! WHAT ARE YOU THINKING??!!
New Haven,
Why are you shouting?
Tom
CAZEPHER, Thanks for filling in the gaps in my knowledge. I should have remembered some of the small switchers that operated fireless from house steam so therefore enough pressure is often present. I may know all about race cars, but the more i learn about locomotives, the more i realize i know very little indeed. J.R.