All those hoses on the pilot

Model Railroader Prototype information for the modeler
1

So I’m getting ready to detail my first locomotives ever (after acquiring a pair of undecorated BB GP40-2s for my freelance railroad). At first, I was going to detail them as old Rio Grande units, but mainly because I have the Detailing Diesel Locomotives book and it’s got a step-by-step for just that. After thinking it over, I decided to just sort of wing it and claim that the railroad was flush enough with cash to acquire its GP40-2s new with their own options.

To this end, I now have to do some figuring out what those options were.

I know that the hose next to the coupler is the air line for the brakes, all the whiskers hanging through the holes in the plow (if there’s a plow obviously) are the MU hoses, and that there’s a big fat hose plugged into the MU receptacle that can be found in various places.

So my questions:

  1. what does that big fat hose do? Sometimes I see the hose stowed on the pilot and other times I see it’s empty socket. Also, is there any reason why the receptacle can be found on the top of the pilot near the base of a handrail stanchion or down mixed in with the ditch lights, other than “that’s just want I wanted?” Why do some locomotives have more than one of them?

  2. What’s the reasoning behind the wide variety of hoses down on the pilot? Some are sporting a total of eight, others four, some have patterns like HHHH Coupler HxHH. Easiest way out is to just use the four hoses on each side of the coupler and not modify the part, of course, But I’d sure like to know why UP seems to have an xHxH C HHHX pattern.

2

The three or four on the side are for main air reservoir, independent brake, and the bail-off on the independent (release loco brakes when the train brakes are applied). The 4th would be for sanders.

Extras on the opposite side are just to make it easier to hook up regardless of the orientation of the two locos. The lines are duplicated, so the hoses can just be crossed over or hooked straight through, as long as the right hose connects tot he right hose.

–Randy

3

The big fat hose is for electrical connections. Lights, controls, etc. I’m not familiar with the details.

Different railroad mechnical depts had different preferences or it could just be they were located differently by the mfg depending on production date.

What appears to be a second receptacle is, I beleive, just a dummy plug to servce as a place to tie down the loose end of the cord, although it might also be a duplicate set of connections as with the air lines.

4

The main hose as you’re calling it actually not a hose, but an electrical connection cable as said above. It can be found with red accents. It’s for MUing the locos. You’re correct about the main air next to the coupler. Many times this MUing cable is left on the loco hanging above the coupler on brackets when not connected. I want to say I’ve seen them with spring supports sometimes, but my memory is not for sure?

BTW, the independent air mentioned above is for the loco brakes only and those mu’d to it, hence the word independent. The contols are identified with an independent air application seperate from train brakes. So, you can see why it takes longer to lash up mu’d locos but hardly any time to build up the air for the loco consist.

Richard

5

Oh, I’d figured the electrical would have been down with all the others instead of up on its own. Also had no idea there were could be one for sand.

I take it there should be a receptacle for the electrical on the nose and rear? Wouldn’t make much sense to just have it on the front. Pictures of the rear pilots are much less common.

6

I’m not aware of any sand connection. The MU cable will activate the sand drop. Yes, there are receptacles on each end of the loco. The attachment points can be on top of the anti climber or underneath. Most if not all newer locos are underneath. I’m pretty sure that the location is determined by the railroad when ordered.

Richard

7

It doesn’t carry sand, it’s yet another air hose. This was listed as not being very common since most of the time the sanders are electrically actuated, even if it is air that blows the sand.

The connections have to be on both ends, because locos are not always lashed up nose to tail. With 4 units, you may have the front two nose to tail, and the rear two nose to tail but facing the other way, so the 2nd and 3rd unit are connected rear to rear. Or maybe 3 face forward and 1 faces backwards. Usually there is at least one facing each direction so there is always a cab in front when running around the train.

–Randy

8

Rear end of a MP15AC.

Note the extra bracket for a hose on either side of the 3. This was for air-activated sanders on older engines. Newer ones send sanding commands through the MU cable. The placement of the MU receptacle varies. Older engines generally have them above the walkways, newer ones lower, like this one. The higher ones helped when MUing with older engines, like F-units, which had their MU connections up much higher, like above the back door, or by the front upper headlight.

Front of the same unit.

9

Forth hose is for passenger called an ‘signal line’, there is a whisle in the cab by the engeneer, when the conductor/s in the passenger car want’s to notify the engeneer of problems or instructions, he could pull his signal cord in the passenger car and it would blow a whistle in the locomotive cab, the whistle was located either on the brake stand or above the engeneers window about 20 inches in front.

Signals were short and long blast, repesinting verious problems and or instructions from the conductor, as he was the boss…Was the same on all railroads (FRR)

All hoses on all railroad’s are located in the same standard L to R order on the pilot(Fed Regs)

Of course if the conductor wanted an emergency stop he could big hole it from the passenger car of which was to the Train line.

BTW the “sander hose” was also like the signal line , by air pressure it activated the mechanical sander relay valve at the bottom of the sand box, of which used engine supply air to force the sand down the hose the the wheels.

A bit off topic but passenger trains brakes set up from the back of train to the front, so the train could be streched out and not jarring the passengers comming in or out of stations

Freight is set from the front to the back of the train

10

Nope … train air brakes set/release the same way regardless of passenger or freight (closest to where the air pressure changes - braking from the locomotive, conductor at the rear, or a break somewhere in the middle and release from the locomotive rearward).

There are a few caveats with passenger service brake systems as compared to freight, but that’s mainly centered around how they release, and operating pressures.

11

For stretch braking, the engineer can push down on the train brake handle to bail off the loco brakes, while maintaining the brake application to the rest of the train.

–Randy

12

well, yeah, you would bail off the loco in either case – else it’s set up before the first (few) car(s), and the train is pushing it…

13

Here is a link to a site that explains many things in railroading including MU systems. It’s a UK site but covers subjects in N America as well.

http://www.railway-technical.com/us-musp.shtml

MarkH

14

I really dont want to act like a know it all, which we never know it all (this I have learened in my 74 years, LOL) nor want to have anyone thinking Im apearing to be talking down to anyone, this is not my intention what so ever.but let me give a bit of backgroud of where Im comming from

I served a four year indentured Apprintiship for the railroad as a Railroad machinist, Apprintiship on record at Federal bureu of records in DC.FRA locomotive inspection at WP an SP. Have worked rebuilding all types of air brake equpment, and all componets of locomotives including injectors, govenors, knuckle to knuckle, reguarding to the machanical trades including FRA inspection of inbound and out bound units and responsible for air test and have signed more #5 forms with my name on the line 15 to 30 per day, if there was a failure reguarding an injury after the units were releasted from the shops it could have came back on me… Have also served as a line shop forman and machine shop and wheel shop forman

my apologys for getting off topic and hope I have not offended anyone

If you ever get the chance to get down in the nose of a F and FP 3,7, or 9, at the bottom of the steps on the right side about knee level you will notice a metal square object about a foot square, with lots of steel air lines comming and out of it.

On the front of it is a small plate about 1/2 thick and approx 2in by 5 in long. on the front it has two words, one rightside up, the other upside down, Theres two cap screws holding it in place, It is either “direct air” or “indirect air” which ever you can read. By removing it and turning it over was from freight to passenger service, or vise versa

Passenger cars have air brakes are a bit different, not much, but different. You all know very well how freight brakes work, from front (powere end) to uncle fred, you can hear the slack working toward the back when big holed.

Passenger cars set from the bac

15

John,
What you are saying about passenger car brakes setting up from the rear forward would require a second trainline passing through the entire train in order for the air to escape from the rear of the rear car first. Can you imagine how much longer a brake application would take to set up doing something like that? No way!

I can just imagine the jerk a passenger train would have if the brakes set up from the rear! Of course, if the crewman dumped the air on the rear car they would set up from the rear.

With the lead unit automatic brake valve set up in “Frt”, the only way to get the train brakes to release (after an application has been made) is to put the handle in full “release”.

With the lead unit automatic brake valve set up in “Pass”, after an application has been made, the train brakes can be regulated by moving the brake handle just as one does with the independent brake. Of course the passenger cars must have the proper brake equipment that allows for graduated release, otherwise, the engine has to be set up in “Frt”. Consists of passenger cars with mixed brake schedules will have to be operated in “Frt”.

Needless to say that running a freight train with the automatic set to “Pass” will ruin your whole day!

16

I can see where your comming from. However I still reseve not only my openion, but with actual experience which dont mean much, But I love my Railroad Reire ment checks

Im not argueing with you in any way, however could you explain to me how an engenneer can strech out a train. From the front without jarring the heck out of the clients, the slack is inceased by each coupler, and that slack is added to the next, at the final car (observation it would have the total slack strech of all couplings, including the lead units.

When slack is starting from the back, each car is only affected by the slack at its front knuckle, and only has the slack between knuckles of that car, as the ttrailing cars are already streched. (Were not Talking Emergency braking, that instantanious at the moment of pressure drop)

Case in point. I was sent out on the road with an electican to a Freight consist that lost power in the feather river canyon. We had full RPM, but no power, as the generators were not excited.

The electrician was openng the electrical controll pannels and I went back throught the units checking if the back units air selection and control pannels if set corectly.

Back in the Cab the electrician was powering engines and it jerked rather violenty.

This did this several times, was like a beginner learning how to drive a stick shift, lots of lerching LOL. Engines powered holding load,and we got back on the main and ran for five minits and powere dropped tthen several seconds later powered up. LOL The conductor yelled severl times over the radio, from the caboose, because the total slack of all combined cars were jerking the heck out of them, by his voice he was beond being miffed, "This ain noxxxxxxxx no xxxxpassenger train, knock it off, I could actually hear the slack rattle over the radio as he got another strech.

The finnaly after about fifteen minits The electrician removed the dash pannel and I held it from behind, we

17

Somehow, this thread went from the assignment of air and electrical couplings for Multiple Unit operation of diesels to the finer points of slack control and direct vs. graduated release of air brakes on passenger and freight equipment.

From what I have gathered in my time spent with passenger equipment and related studies—the railroads started taking a deeper interest in slack control with the development of the Type H tightlock coupler adopted by the AAR Mechanical Division in 1937. In 1956 the type CS controlled slack coupler which had additional rubber shock pads in the knuckle and a sprung “guard arm plunger” which practically eliminated slack between mated type H-CS couplers. This, in combination with rubber isolated draft gear and the hevily sprung buffer plates mounted as part of the underframe design, almost made a complete passenger train operate as a single unit with very little slack and what slack there was is cushioned extensively.

I’ve been in the last vestibule of 15 or 18 car passenger trains and heard the engineer release the automatic brakes prior to leaving and you could feel the cars roll back slightly as the spring compression was relieved from the buffers.

As the train departed the feeling of movement was barely perceptible all the way at the rear end. Train crews would often comment about which engineer they had that day, and their train handling skills were frequently commented on, weather good or bad.

Big Jim is absolutely correct that unless the train-line can be bled off from the rear (AFAIK an EOT will only go into emergency, you can’t make a service reduction from it) the only main difference, and seeming sticking point here is the slightly higher trainline pressure and the direct or g-r-a-d-u-a-t-e-d release for passenger service.

During brake tests you can hear an intermittent hissing as the brakes are released in passenger service. I used to have to prepare passenger cars for special moves in freight service by rot

18

John,
First, a passenger car’s draft gear is built tighter and consists will have much less slack than do freight cars. As a brake reduction is made, each car starts to set up in series front to rear as the signal (read: brake pipe reduction) reaches the control valve. The braking effort in each car gradually increases front to rear gradually taking the slack out of the train. Also, by using multiple light brake pipe reductions, smooth train handling can be achieved.

The same thing can be achieved on a freight train even with the additional slack.

In either case, you just have to know how to do it.

19

Does anyone know if someone makes that big electrical cable? I can’t find anything on Walthers and none of the magazines I have seem to have an article that mentions one being used in a detailing project.

20

http://www.detailswest.com/Details%20West%20Catalog%202007.pdf

Part Numbers 218 thru 236

You can order the parts from HIghball Graphics http://www.mgdecals.com/homepage.htm or Walthers.