# What was/is Protection and how did/does it work?



## Jerrys RR (Jun 28, 2010)

I have read frequent references to "Protection" and I don't quite know how it works. As an example in a current book it says "Cotton Belt is able to use only two diesel units to protect 386 through freight miles..."

What was/is Protection and how did/does it work?

Is it something that is outdated or is it still used today?

Thanks,

Jerry


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## jgallaway81 (Jan 5, 2009)

Without a larger chunk of the text, I may be misinterpreting the usage, but as I understand the usage here, they are referring to the train's locomotives... in today's slang "units" or "power". (IE: What's the 11J's power today? It has two units, one wide-body, one 4-axle)

Protection is still very much in use today, though its reasons have changed a bit.

The most common usage (in my area anyways) is a result of the Hours of Service Act. NS 21m is one of the hottest UPS/US Mail truck trains on the Northern region. Once it leaves Harrisburg yard, it has to make it from CP-Rockville (Milepost PT-109, Pittsburgh Line) to Conway Yard (MP PC23, Ft. Wayne Line - equivalent to PT377, Pittsburgh Line ends at 354) with a stop to setoff and pickup cars at Pitcairn Yard (PT337.9). By the time the train reaches the Altoona area, the dispatchers will have a good idea if the train crew has enough time available under the Hours of Service Act to make the rest of the trip. If it is getting close to the cut-off time, a helper will usually be held in the hole "to protect". Basically giving the dispatcher the option of increasing the train's max average speed by supplying additional horsepower for the climbs, and just as vital, additional dynamic braking effort for the down-grade moves. The additional braking allows the train to avoid using its air brakes in many sections since the rear-end helper can "grab hold" of the train and hold back part, reducing the work load of the dynamics on the lead units.


In places where the terrain changes within the length of the train, rear-end helpers can make a lot of difference... a heavy freight may have to come into a steep downgrade at 20mph in order to ensure it doesn't end up speeding by the time it gets to the bottom. With the helpers, they now have the ability to enter that grade at 30mph or more, knowing they have additional braking effort to help out.


Another spot that they help increase train speed is the flats near 260 where the track pans were located for the steam engines. A downhill train will come into "the pans" (as it is still referenced) bunched up with dynamic brake applied on the head end. Even in minimum dynamic, the train will slow significantly, depending on weight & length, possibly stall. So the engineer must now transition from dynamic braking to throttle in order to keep the train rolling. Then, about a mile from where they began the railroad goes downhill again. So now he/she must now get the train bunched back up (it had been stretched because of going into throttle) and get the dynamic brake spooled back up to keep control of the train. With a helper, the engineer on the lead power reduces the dynamic to a point just enough to keep the train bunched. The difference is now the helpers throttle-up and shove the entire train through the flat area. As the head end reaches the downgrade portion, the leader will begin increasing the dynamic, while the helper begins throttling off, effectively handing off the train's acceleration from the helpers to gravity.


And because Pennsy couldn't print their own money and make HUGE massive changes to the Earth's surface, there are undulations to the terrain from Johnstown to Pittsburgh that keep an engineer on a hotshot train on his/her toes.


In the older days, when mechanical failures were all to frequent, especially on them new-fangled diesel contraptions, often steam locomotives would be stationed at strategic points across the railroad in order to "protect" a passenger schedule from a locomotive failure.


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## Tom Parkins (Jan 2, 2008)

Protection has many uses in different RR context. The protect locomotive, or protection power mentioned above is a good example. In some cases Amtrak positions extra locomotives as protection power, but it is always a source of discussion on railfan forums, because they never seemed to be positioned in the right place. 

Special trains may be shadowed by protection power. When Ross Rowland ran the C&O 614 on New Jersey Transit to Port Jervis, some NJT diesels lead a few blocks ahead as protect power. 


Protection can also apply to tracks. PRR in Delaware had a 4 track main line. If a passenger train made a stop at a station using the inner tracks, the dispatcher would tell the crew that they are protected on track 1 (an outside track). That means no trains could pass while passengers unloaded. 

MofW personnel are protected from other trains when working on the tracks. 

Three point protection was mandated with engine crews when work was done on the train between cars. 3 point protection was 1) reverser in neutral, 2) throttle stopped, 3) brakes set. I recall that different railroads had different terminology for basically the same thing. 


Probably a few more examples we missed. 

Tom


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## Jerrys RR (Jun 28, 2010)

I was going to try to clarify what the author meant regarding my original question about protection but as the explanations expanded I realized that I have heard the terms "protect" and "protection" in many applications. It seems that the person or persons using the terms assume the reader or listener is somehow going to know exactly what it is that they are referring to (such as the author of the book I am reading).

The multitude of definitions at least makes me realize that the answer(s) were not as obvious as was apparently assumed by the author of the book and by others using the terms with non-railroad audiences.

Thanks,

Jerry


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