How does the engineer in the second engine know how much throttle it takes to be pushing (helping) rather then dragging on the lead engine?
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Seat of the pants.
Rusty
could the power of the second unit overpower the braking of the lead engine.
Originally Posted by L.I.TRAIN:
could the power of the second unit overpower the braking of the lead engine.
Steam locomotives do not use their driver brakes anyway, as the heat from the brake shoe friction could loosen the tires (the steel tires are heat-shrunk onto the cast drive wheels). Only the train brakes are used, so to answer your question,,,,,,no.
Bobby, the Engineer on second engines normally worked the engine harder than the engine on the point where full horsepower was not required. The Engineer on the front engine controlled the air brakes and the speed. All Engineers used the independent brake valve to keep the engine brakes from applying when the train brakes were applied, first, for the reason Hot Water explained, as well as, secondarily, to manage the coupler slack (which can be violent if the engine brakes are applied and released along with the train brakes). In undulating territory, it was more complicated, but Rusty's reply applied there, and the second engine was first to increase throttle and last to reduce throttle. It is not as complicated as brain surgery, but the Engineers had to know their jobs and there were not "processes" to follow.
It is NOT the brakes on the engine which stops a train. It is the brakes on the TRAIN that stops the train.
Thanks for your replies. I had a thought that the answer to my question would be seat-of-the-pants and experience.
I read with interest a post regarding MU control in steam engines that double head with diesels. Is MU control a practice today with double heading steam engines?
I also think that radio or intercom communication between steam crews makes a big difference in throttle settings.
Originally Posted by Bobby Ogage:
Thanks for your replies. I had a thought that the answer to my question would be seat-of-the-pants and experience.
I read with interest a post regarding MU control in steam engines that double head with diesels. Is MU control a practice today with double heading steam engines?
No. There is now way to MU two or more steam locomotives, since all the controls are manual/mechanical, i.e. no electricity.
I also think that radio or intercom communication between steam crews makes a big difference in throttle settings.
What "radio or intercom" between steam crews? No such thing.
"radio or intercom communication between steam crews"
The railroads used whistle and hand signals to communicate up till the 1960's at least. Some jobs still used hand signals for years after radios were available since they worked well and were more reliable than the early radios. ......DaveB
Originally Posted by Hot Water:
Originally Posted by Bobby Ogage:
Thanks for your replies. I had a thought that the answer to my question would be seat-of-the-pants and experience.
I read with interest a post regarding MU control in steam engines that double head with diesels. Is MU control a practice today with double heading steam engines?
No. There is now way to MU two or more steam locomotives, since all the controls are manual/mechanical, i.e. no electricity.
I also think that radio or intercom communication between steam crews makes a big difference in throttle settings.
What "radio or intercom" between steam crews? No such thing.
I don't want to put words in anyone's mouth but I believe Bobby meant radio use between steam crews in a hypothetical doubleheader in the present day.
Out of curiosity, couldn't doubleheading PRR engine crews have communicated via the old Trainphone system, or was that strictly cab to base station and vice versa?
Were you on board when 4449 and 844 entered LAUPT together in 1989 for the 50th Anniversary and was that move coordinated via radio?
Originally Posted by Nick Chillianis:
Originally Posted by Hot Water:
Originally Posted by Bobby Ogage:
Thanks for your replies. I had a thought that the answer to my question would be seat-of-the-pants and experience.
I read with interest a post regarding MU control in steam engines that double head with diesels. Is MU control a practice today with double heading steam engines?
No. There is now way to MU two or more steam locomotives, since all the controls are manual/mechanical, i.e. no electricity.
I also think that radio or intercom communication between steam crews makes a big difference in throttle settings.
What "radio or intercom" between steam crews? No such thing.
I don't want to put words in anyone's mouth but I believe Bobby meant radio use between steam crews in a hypothetical doubleheader in the present day.
There is really no reason to "communicate" between two or more steam locomotives, as the lead Engineer has control of the train (speed and air), and the Engineer on the second locomotive is able to tell pretty easily when the the lead man needs "help".
Out of curiosity, couldn't doubleheading PRR engine crews have communicated via the old Trainphone system, or was that strictly cab to base station and vice versa?
Again, there would be no need for that, as both crews were well qualified on their own territory.
Were you on board when 4449 and 844 entered LAUPT together in 1989 for the 50th Anniversary and was that move coordinated via radio?
Yes, I was Fireman on SP4449, but there really was no radio communication, once we were in sight of UP8444/844. The UP had the much longer & heavier passenger train, so the Engineer on 4449 (Doyle McCormack) was able to easily match our speed to the UP, so that we came together side-by-side well prior to entering LAUPT.
Made my first trip on a double header at around 8 years old. Night time too. After coupling onto the train and getting under way my dad told me to duck down going by the Superintendents office close to the switch where we left town. Had to duck down at every open train order office. I can't remember for sure but I think we had about 30 cars of ballast and 2 engines, maybe Mikado or 10 wheelers nothing big. It was a short haul and returned (van hop) caboose only. The head end brakeman gave up his seat and went back to the caboose. Kind of fun.
Most steam crews would know exactly when to push or let off by knowing the road.
Question.... when the train brake is applied on a steam engine , do you still have to bail off the independent (engine brake? ) like you might on a diesel. Or put another way does it apply when automatic is applied?
Have you ever heard of cutting off the engine to spot at a water spout on a heavy down hill grade with a full tonnage train.? If you over run the spout you can't back up (too heavy) 
Originally Posted by Gregg:
Made my first trip on a double header at around 8 years old. Night time too. After coupling onto the train and getting under way my dad told me to duck down going by the Superintendents office close to the switch where we left town. Had to duck down at every open train order office. I can't remember for sure but I think we had about 30 cars of ballast and 2 engines, maybe Mikado or 10 wheelers nothing big. It was a short haul and returned (van hop) caboose only. The head end brakeman gave up his seat and went back to the caboose. Kind of fun.
Most steam crews would know exactly when to push or let off by knowing the road.
Question.... when the train brake is applied on a steam engine , do you still have to bail off the independent (engine brake? ) like you might on a diesel. Or put another way does it apply when automatic is applied?
Absolutely YES! The Engineer NEVER allows the brakes to apply on the drive wheels, for fear of overheating the tires. In fact, railroads such as SP and UP, had "mountain cocks" which cut-out the brakes on just the drive wheels, for long down grade braking. The SP even had water spray systems on their locomotives to cool the engine truck wheels, trailing truck wheels, and tender wheels during heavy braking on 2.2% grades.
Have you ever heard of cutting off the engine to spot at a water spout on a heavy down hill grade with a full tonnage train.? If you over run the spout you can't back up (too heavy)
Yes, that was standard procedure on many railroads, when operating on heavy grades, either up or down.
On the Long Island Rail Road there were regular instances where diesels had to be double headed.
The twelve FM C-Liners, eight 2000hp CPA20-5, and four 2400hp CPA24-5, were built without multiple unit capability (penny wise, pound foolish). As a result whenever a train was too heavy for a single C-liner they had to be double headed with two crews, and the engines run "elephant" style.
Stuart
