Loose Consist Brake Pressure

[charland]

I was looking at a train schedule this afternoon for a new route. It's essentially a branchline that connect to the mainline of the same railroad. The schedule is set up so the mainline way freight arrives at the junction, drops off a dozen cars in the yard, gets out of the way and the branchline train arrives, exchanges cars and departs. Thus was about the same situation as the Conrail route I put out recently... Conrail way freight arrived in Fonda, dropped cars in the yard and the FJ&G would come in, exchange cars and leave.

The point of what I'm saying is in both cases the cars dropped off by the mainline train are represented as "Loose Consists". In real life these cars would still have the air pressure that would have just had when the mainline train put them in the yard, the branchline train picking them up wouldn't have to sit there for 15 minutes charging the cars before they could hit the road.

Is there a way that we could tell TSRE that "this loose consist has 90 pounds of brake pressure"? I know we can skip the long pumping time by using SHIFT+/ but somehow that feels like cheating!

Paul :-)

[wwhall]

^According to most railroad operating rules, your assumption is incorrect. Cars set out will generally have all the air drained from them. This done for several reasons: First, rules require enough handbrakes to be set on the cars to prevent them from rolling. If air remains in the cars, it may be the air in the brake reservoirs holding the cars, not the handbrakes. Draining the air assures that the handbrakes are holding the cars. Second, related to the first. If air remains in the air brake reservoirs, it may not be possible for the handbrakes to be completely set. I've seen train crews set handbrakes on cars, then drain the air from the brake system, and then go back and further tighten handbrakes. Third, if air remains set on set-out cars, that air may eventually leak out of the brake reservoirs and release the air brakes. If sufficient handbrakes are not set, the cars may actually start rolling.

A common practice (though a rules violation on most railroads), when temporarily cutting locomotives off from a train to make a switching move, is to "bottle the air" in the train--that is, close the angle cock on the car coupled to the locomotive before uncoupling so that the train line air does not exhaust and cause the train cars to go into emergency brake application. This saves air pump-time when the loco is recoupled to the cars.

All of this shows the difference between MSTS, which was essentially a game, and OR, which is a simulation. Yes, pumping up the cars of a loose consist when picked up can take considerable time--just like it does in real railroading. To sum up, if one picks up a loose consist with the air already pumped up, those cars were spotted in violation of most railroads' rules. I vote for loose consists to have empty air reservoirs, as they should in prototypical railroading. If one wants to play OR as a game instead of a simulation, then use the initialize brakes function to "cheat."

[charland]

So you are saying if one freight drops a dozen cars in a yard knowing that in ten minutes they will be picked up a second train they would dump the air and the second train would have to spend fifteen minutes pumping the air back up. Watched a lot of train doing switching over the years and never saw that unless the cars they were dropping off were going to stay in place for hours or days.

Paul

[wwhall]

^Yes, if the crew is following the rules, they will NOT bottle the air. I know a lot of crews violate the rules, but it is a dangerous practice. The tragedy at Lac-Megantic was a variation on bottling the air. In that disaster, the crew did not set sufficient handbrakes, did not check to see if handbrakes would hold the train, and--instead--relied on a clearly malfunctioning locomotive to keep the air pumped up on the train. A whole cafeteria of rules violations. Subsequently, the locomotive's prime mover died, and the effectively "bottled air" in the train bled off, eventually allowing the air brakes to release. The resulting runaway nearly destroyed the town and killed several people. As my railroader friends say, "A little rules violation is like being just a little bit pregnant." And, in so many railroad derailments, wrecks, etc., the cause often is a few small rules violations that, together, precipitate a major disaster.

[charland]

Where did you find these rules? I've just gone through the UCOR Revision of1962 and didn't find a word about setting cars out in a yard or siding. Not setting enough handbrakes is a mistake for sure, it was covered in the UCOR rule book decades before Megantic..

Paul :-)

[rdayt]

Wrong Book.



Randy

[charland]

Thanks Randy,

I'll have to find that, I think I've seen a PDF on the CPR Historical Society website.

I think there would be a different interpretation to the rule it the cut of cars being set out were to be picked up immediately. I do know a couple of former conductors I'll ask.

Paul :-)

[rdayt]

I've got 10 years of train service with BN. Brakeman and conductor.
We never left cars anywhere with bottled air. Besides, it's easier to set hand brakes after you pop the air.
As for leaving cars for another train, you're never really sure when or even if it'll ever show up.
CYA. Always.

Randy

[charland]

I'm just a little bewildered I've never seen this, OK as a railfan. It doesn't make any sense to me to have one train drop cars in a siding and dump the air when they know there is a second train minutes away going to pick them up.

Paul :-)

[rdayt]

That train that's minutes away is just about to go on the ground and then everybody that knows about your setout will forget about it.

Randy

[charland]

Here's a great explanation from my friend Andrew who was a conductor for CN ut of Halifax for years:

"Hi Paul,

The practice you're describing is known as "bottling the air". This procedure was once widely used and is now forbidden.

What used to happen is that the engineer would take a full application and wait for the air to finish exhausting. This would set the brakes fully on the cars to be left and at that point the brakeman would set handbrakes (back in the day when this was a very simple formula), close the angle cocks and go. The problems are that the brake systems are seldom entirely air tight, and air can bleed out of the cylinder over time which releases it or degrades the effectiveness. Daytime heating can raise the pressure in the line enough for the cars to think that the brakes are being commanded to be released. Theoretically, if the handbrakes were tested properly and found to be effective, things shouldn't move, but handbrakes are sometimes not really effective either, and pushing or pulling on a fully set brake might make it seem like the handbrake is doing the work when it isn't.

So what happens now is the cut is left, handbrakes applied (as per whatever version of Rule 112 is floating around now, it's basically a book in itself post Lac-Megantic) and tests. The angle cock is closed on the portion that is remaining with the engine and the air is allowed to exhaust. This sends the brake pipe pressure to 0 PSI and dumps the full pressure from the service and emergency portions of the reservoir into the brake cylinder. At least one angle cock is left open. This allows the brake system to constantly be at 0 PSI regardless of what is happening as far as daytime heating (forgetting that atmospheric pressure is standard 14.5, which I've encountered in OR brake settings and I have no idea if OR determines 14.5 is 0 or not).

This means that the air brake system is left in Emergency. This, too, can bleed itself off over time. If a crew wanted to switch without air, they can pull the bleed valves located in the middle of each car and bleed the brakes off that way. There is no requirement for a real life yard or transfer movement to connect hoses and charge up the system, though a local move might do it depending on how far they want to travel and if they want to abide by the rules governing a Transfer Movement. If they have an SBU with them, they'll probably pump it up and throw the SBU on so they don't have to dawdle everywhere at 15 MPH.

The good news is that OpenRails can do this! Once coupled on, F9 brings up the car menu (otherwise there's no way that I'm aware of to access a menu for loose consists). There is an option toward the bottom of this menu to open/close bleed valves. I don't think OpenRails leaves static consists with the emergency brakes applied, but it was always good practice in 1:1 to give the rods a pull anyway as you went by, particularly if you weren't planning to use air. This way you're not dragging one around with brakes on which can be a problem if it's empty or light (like a flat car). I regularly switch without air using this feature in OpenRails, I have even managed a kick, sending the car down the track with no air on its own!

Hope this long-winded explanation helps. The long and short is that bottling used to be a practice used to save time, and it did save time, but too many accidents over the years have reduced its use to either being entirely forbidden or used only under very specific circumstances that would be dictated in the General Operating Instructions for that railway (everyone is a bit different, but the main rule is that the GOI cannot be more permissive that the CROR).

Andrew"

Seeing as the route I'm tinkering with is set in 1963, I'll keep doing what I've been doing.

Paul :-)

[derekmorton]

>I have even managed a kick, sending the car down the track with no air on its own!

I too have done that on several of your routes, but even when in manual mode, the path code does some strange things, I have seen sections that are added to the path with no connections to other paths.

[CSRX]

When CPKC drags their 7-10k foot train into Brownville Jct for the EMR to hook on as soon as CPKC breaks away, they still dump off the whole train and we end up sitting for 10-15 minutes to pump up to 75 pounds (under the CROR rules) before we can move.

When we were dropping traffic off for CSX, we would set a sufficient amount of handbrakes, test the hold on them, dump it off, run around, and put it on yard air, which releases the brakes. All was well until one of their conductors decided to bottle the air, release handbrakes, and the cars rolled out of the siding and slammed into the side of their locomotives..


Yard air, would be the only time you wouldn't need to pump the air brakes if done right, which unfortunately, I don't think this is something we will see in ORTS.

[charland]

I did find a new Air Brake and Train Handling Rules book online yesterday that was published in 2022 as a result from the Lac Megantic accident. I'd like to find the older version of this to see what it says about my switching situation. It wasn't an uncommon practice, just wondering if it was actually in a rule book that covered it or not. Different times, different rules.

Paul :-)

[wwhall]

Most railroads also have rules that air hoses must be connected and brakes functioning on passenger cars when they are moved, no matter whether the cars are occupied or not. While some railroads permit it, switching cars with no air connected and the brakes bled off can also be dangerous. Some years back I witnessed this go bad when a freight crew was making a switching move. The crew had coupled to two empty cars. They did not connect air hoses, nor did they "stretch" the coupling to see if they had successfully made the joint. The yard tracks where they were switching had a slight upgrade, then tipped downgrade. The crew was shoving the cars up the upgrade at about 6-8 mph. When the loco and cars tipped downgrade, the cars uncoupled from the locomotive (the pin hadn't dropped and crew hadn't confirmed that it had). Well, it was off to the races. The cars quickly gained speed. Before the train crew could react, the cars ran through several switches, finally rolling to stop nearly a mile away when the grade leveled out. The cars also crossed several unprotected grade crossings. The Roadmaster had to pull a track crew off of another important job miles away to repair all the run-through switches. Because of all the damaged track, the mess became a reportable incident to the FRA. I would surmise that the train crew was severely disciplined, if not fired.