Steam & Excursion > A Very Short Passenger Train With Plenty Of Power To Pull It!

While mainline steam power on most passenger trains was big enough to meet the needs of the trains they were assigned to, there were times that the power assigned greatly exceeded the capacity of the train they pulled. Here is one such train.

In this photo we see Northern Pacific's 4-6-2 #2260 at the head-end of a short passenger train running through a small town in Montana. #2260 was part of NP's Q-6 Class engines turned out by ALCO in 1923. She boasted 44,080 pounds of tractive effort which would be more than enough for this short train that we finds herself assigned to on this day.

NP in this district followed the rule of, its better to have too much power than not enough.

Martin



Edited 4 time(s). Last edit at 06/14/18 03:33 by LoggerHogger.

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Plains Montana??

http://mcgowangrocery.com/our-story.html

On the Clark Fork west of Paradise

Bob Jordan

I would say you nailed the location. Thanks.

Martin

LoggerHogger Wrote:
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> I would say you nailed the location. Thanks.
>
> Martin


Thank You! for all the great posts. Was surprised to find that info.

Bob

A very interesting photo.
Thanks for posting.
ALLEN

Thanks for posting, a classic.
I would appreciate comments from experienced engineers about what it would be like to brake such a short train.
Would the engine brakes be bailed off and only the train brakes used for station stops? For descending grades?
TIA

Even in black and white it looks like a hot summer day. Great photo!

Posted from Android

railstiesballast Wrote:
-------------------------------------------------------
> Thanks for posting, a classic.
> I would appreciate comments from experienced
> engineers about what it would be like to brake
> such a short train.
> Would the engine brakes be bailed off and only the
> train brakes used for station stops? For
> descending grades?
> TIA

The engine probably has more braking power then the two passenger cars.

Back in the day right before Amtrak the Penn Central was running a train between Harrisburg and Buffalo which consisted of a baggage car and coach just like this one. Usually the motive power consisted of one E8 or E7. However on occasion, probably to balance power, the had two engines to pull the two cars.

railstiesballast Wrote:
-------------------------------------------------------
> Thanks for posting, a classic.
> I would appreciate comments from experienced
> engineers about what it would be like to brake
> such a short train.
> Would the engine brakes be bailed off and only the
> train brakes used for station stops? For
> descending grades?
> TIA

Well, it's been over 36 hours and nobody has stepped up to comment so, with trepidation, I'll take a shot at it with full knowledge of the pitfalls involved.
I'm using Southern Pacific's rule book from 1951 as reference and with acknowledgement that Northern Pacific most likely had something similar to say to their engineers.

First, understand that the cars in Martin's photo were most likely equipped with air brake control valves that had the 'graduated release' feature
enabled; a simple procedure for a carman to accomplish without sending the car to the rip track. 'Graduated release' is a function that allows the engineer to apply the train brakes while moving at higher speeds with sufficient force to bring the train speed down relatively quickly in preparation for stopping. This ability is a boon to both the railroad, to operate their passenger trains at higher scheduled speeds as well as the comfort of the passengers in the diner who arrive at their destinations sooner, with less slack action and without wearing their soup du jour! Not a textbook definition but you get the picture.

In the matter of Service Stops, SP's 1951 Rule 42 states: "Service stop with 16 cars or less with 75% or more graduated release equipment. The brakes should be applied making an initial reduction of 6 to 8 pounds. After the slack has become adjusted, an additional brake pipe reduction of sufficient amount should be made to stop short of objective; if held fully applied. When speed has been reduced sufficiently start a release of the brake cylinder pressure by moving the brake valve handle to release, then back to lap position when handling trains of 10 cars or more, or running position then back to lap with less than 10 cars. This procedure should be continued, holding light brake cylinder pressure applied, throttle closed. Necessity for making further brake pipe reductions to complete the stop should be avoided."

I'll not go into the subtleties of the differences between 'release' and 'running' on the automatic brake valves of steam locomotives of that day; leaving that chore to others more inclined and knowledgeable to do so, but do notice the wording regarding "...light brake cylinder pressure applied...". One very big NO NO is to develop excessive heat on steam locomotive driving wheels with the chance of slipping a driver tire which would be the likely result of too much brake cylinder pressure over the distance required to bring the
train to a smooth stop and in the case of Martin's NP 2260 and its two car train, with a high engine weight to train weight ratio, it could be a very real possibility. The successful locomotive engineer would have to be vigilantly aware of the situation and take steps to keep driver brake cylinder pressure in check.

I readily acknowledge that in my career I never actually operated a steam locomotive and I suspect that there were (are) certain manipulations of the automatic brake valve,
throttle and reverse lever or combinations of all three that engineers of that era used to, in effect, 'make' their own pressure maintaining feature and methods to allow steam
to enter the cylinders thereby creating a back-pressure which acted to retard the speed. Again, others with knowledge of this will have to help us youngsters. Possibly I'm
trying to mix my diesel days experiences with those of steam and the two don't necessarily blend well.

On the topic of 'running release', as automobile drivers we employ this principle every time we get behind the wheel. To illustrate; as we approach an intersection and the traffic light changes from green to yellow, we begin slowing by applying the brake pedal. If our speed was high enough we apply more brake but as we near the, now red, signal if we don't 'graduate' off the brake we will soon come to an abrupt and uncomfortable stop. Try not 'graduating' and you will soon see what I mean.

So to your question and in my admittedly limited (non steam but certainly diesel era experience on passenger trains), the train (car) brakes will have to do the 'heavy lifting' with a slight assist of the locomotive brakes to complete the stop. As to descending grade situations, in the days prior to dynamic braking the use of retaining valves on the cars was common and timetable special instructions mandated periodic stops to allow for wheel heat radiation.

Charlie



Edited 2 time(s). Last edit at 06/16/18 10:23 by cewherry.