Steam & Excursion > booster question for Wes

On T&P 2-10-4's I was told by engineer that you had to "come out" of the booster by 15 mph and that you had to almost come to complete stop to "re-inguage it".  Those engines had 60% cut off which I assume would make re-ingauge speeds different from from engines with larger cut off numbers.  Would that be correct?

Boosters had eariy versions, and later they developed boosters 
with more capabilities.

So, I'm guessing these 2-10-4 might have had earlier booster variants.
Thus, their operating instructions were best suited for their locos.

More modern booster variants had higher operating speeds for
power boosts, and also could be re-engaged safely at speeds below 
22 mph.  Because the booster gears have conventional-shaped 
gear teeth, the re-engage speed gets very problematic at speeds 
above 24 mph.  There is no 'clutch'!

I don't reccomend trying to re-engage much over 20-mph.

You'd be better-off to come to a stop and maybe try a different solution to your 
hill climbing challenge.

​W.


 



Edited 1 time(s). Last edit at 02/02/25 16:49 by wcamp1472.

1522 used a type C Franklin Booster. It was rated at 21 MPH top speed and Max engagement speed of 12 MPH.  After idling the booster, you would put the engine in the corner and engage the booster by latching a lever over the reverse quadrant which was in a fixed location.  After starting the train when you hooked the engine up the reverse lever would disengage the latch and shut the booster down.  We had a lever to push to cut off steam to it if the booster started slipping.  Frisco was a big user of them.
The type E was good up to 25 MPH and could be engaged up to 15 MPH.
Type E-1 had even higher max speed and engagement speed.
Forward only!
Booster is a great insurance policy.

From our experiences on SP 4449 and having to use the booster, every time that I'm aware of, the speed was down to about 10 MPH, when Doyle engaged the booster. In every case, except one, the use of the booster kept 4449 from stalling. The SP GS-4 locomotives were equipped with the Franklin Railway Supply "High Speed" booster, which could be engaged at speed up to 15 MPH, and used through speed up to above 20 MPH as needed.

On the only one case that the booster did NOT prevent us from stalling, we were going into the designated display sight for the Freedom Train, in some sort of State Park near Charlotte, NC. We we not advised in advance that the grade into the park was VERY STEEP. So, in the wee hours prior to sun rise, we attempted to haul the train into the park site. We were making pretty good speed, about 20 MPH, when every so slowly our steed began to drop. At around 10 MPH, Doyle engaged the booster. Speed still kept dropping, and finally at full throttle, with the booster engaged, 4449 simply just stopped,,,,,,,,,,,,,,no slipping,,,,,,,,,,nothing! Just stopped! Doyle shut everything down and I got the fire back down to a nice spot fire. The old head Pilot Engineer finally said, "Don't worry boys, a diesel is only rated for 1500 tons on this grade.". Doyle told him to get on the radio and have the diesels on the rear of the train push us into the display site, just as the sun was beginning to rise.