how much of a concern is fuel during switching moves, or is John Allen’s Timesaver, where the goal is to make a set of switching moves in as little time as possible, really representative of a real railroad?
It seems wasteful (fuel) to me to move a string of cars a longer distance than necessary when they could be dropped of on nearby sidings, minimizing the number of cars (tonnage) moved but increasing the number of engine reverses and need to switch turnouts.
certainly on a model railroad this is not a concern, and minimizes the number of uncouples which may not be convenient.
The Timesaver, and several switching problems published in Model Railroader during that period, owed a lot to sliding block puzzles and very little to prototype practice.
I’m sure Brakie can go into a lot more detail, but one major consideration with dropping bits and pieces of train here and there is preserving brake integrity and brake line pressure. It isn’t just a matter of opening coupler knuckles. Uncoupling involves closing angle cocks as well as opening knuckles, and recoupling calls for hooking up glad hands, opening angle cocks and getting the brakes to fully release - every time. As you can judge, the time required is MUCH longer than the model coupling process.
While I have not made any detailed fuel consumption studies, I suspect that the least expensive overall approach would be to make just as small a number of cuts and couplings as can be conveniently arranged. Fuel is just one variable, and not necessarily the most expensive one.
In the real world a switch crew will generally try to minimize the number of switching moves. Some old heads were amazingly good at planning the ever-changing daily puzzle very quickly. Their motive had nothing to do with saving fuel, everything to do with finishing the work with the least amount of physical exertion and getting an early quit. That likely also saved fuel as a coincidental bonus by reducing the amount of stop-and-go. Within reason the extra weight of additional cars would have little effect.
If you’re talking fuel consumption only, diesels tend to use fuel based on the load. More fuel = more load. When idling or in the lower throttle notches, a diesel switcher will use very little fuel. Since most switching is conducted at speeds far lower than what would be achieved if the throttle was in Run 8, an engine in this service will use relatively little fuel. The exceptions to this are switchers in yard service and when otherwise handling long cuts of heavy cars.
Although the fuel tanks on a switcher are smaller than on a road engine, it’s possible that a switcher can go for days before visiting the fuel rack. If you did want to included moves for fueling, it would be more like a wild card or joker. It will likely not happen every ops session or shift.
There are so many variables present - Fuel is just a part of it. Most of the time the conductor maps out the ‘moves’ - And this is based on getting the work done with the least amount of work. Some large industries will tell you what to switch & when - they need to have loads moved out and empties placed for loading - Time is money.
Fuel costs are really not part of this - I remember that the CB&Q had a SW1 assigned as the ‘town’ engine for Winona, MN. It lived there all week long, and was dragged to La Crosse, WI on the week-end for servicing. It sat in Winona idling all day/night long when not working on that 600 gallon tank of fuel.
Here in Rochester, MN the DM&E(CP) has a GP38 that has a 2,600 or 3,000 gallon fuel tank. It is shut off in the evening, and makes a W/E trek to Waseca for servicing. Many of the new engines have ‘hot start’ or other automatic starting systems that will auto start the engine if the temp get too cold so they do not freeze up.
First its not the number of moves you make. We never made a move that we didn’t have too nor did we move cars that didn’t need move not so much to save fuel as it was to do our work in a efficient manner.
Time has nothing to do with it since picking up and sitting out a car can take up to thirty minutes in a safe manner.You see time is needed to unlock and open the switch,unlock and open the derail,once you couple on to the car you must ensure the couplers are lined and at least one open, release the hand brake after coupling etc…
As far as dropping cars to be switched later would not be very efficient…If we had facing point setouts we simply switched them out on the return trip unless it was a stub end industrial branch then we would either make a runaround move or better is to have the engine in the middle of the train with a caboose on both ends of the train.Using 2 cabin cars was the norm for some PRR industrial switch jobs.We would put our train back together at a outlaying yard where we had room to work or just make a reverse move back to the yard with the engine in the middle.
As far as fuel…That comes under operating expense and is factored in.
As far as modelers switching cars I try not to laugh at the way they do things-things not only against operating rules and safety rules but,not in a very efficient manner.
I’m sure Brakie can go into a lot more detail, but one major consideration with dropping bits and pieces of train here and there is preserving brake integrity and brake line pressure. It isn’t just a matter of opening coupler knuckles. Uncoupling involves closing angle cocks as well as opening knuckles, and recoupling calls for hooking up glad hands, opening angle cocks and getting the brakes to fully release - every time. As you can judge, the time required is MUCH longer than the model coupling process.
Chuck, in a yard or other “Time Saver” like situations, the cars would likely be handled with the air bled off, and not worried about connecting glad hands, and building up the air in the trainline for each move. Uncoupling would be just a matter of opening the knuckles, and coupling just pushing them together.
In a road switcher situation a car or two here, down the line a couple miles, another 2 or 3 cars and on to the next customer, that would involve all that you mentioned, but not so much in a yard, or other "time saver " situation.
Yes…We need air for the train brakes-this is per the safety and operating rules for safe train operation…
Before we uncoupled from the setouts we would closed the air line valves located on the air pipe,set the hand brake on several cars in the cut to be dropped and then lift the uncoupling bar and make the cut.
Making a pickup of several cars we would walk the cut we was picking up to ensure all air hoses was connected,bleeder and retaining valves in their proper position…We would then look to ensure at least one knuckle was open and then make the joint and we would double check to ensure the coupler pin dropped…We would then connect the air hoses and open the air valve and then we release the hand brakes on the cars we was picking up.