The rail line out behind my office has a slow order somewhere in the next mile that cause the trains to putt-putt by at 5-10 mph. Would an engineer typically ride along at normal speed until he/she was close and jam on the brakes, or just let off the gas a ways back and let the train’s weight slow it down sufficiently? The line is flat and 99% of the traffic is unit trains of grain, ethanol and pink rocks.
Probably a little of both, depending on the actual profile. I wouldn’t use the term “jam on the brakes,” but taking a first service in time to slow down would be appropriate.
Also depends in part on how big a hurry they need to be in (what’s the normal speed there?). If they need to run significantly faster to maintain a schedule, etc, then the transition between track speed and the slow order will be that much more abrupt, in keeping with good train handling.
Looking forward to confirmation from the railroaders, but don’t the computerized systems (like LEADER) automatically calculate the best combination of fuel conservation/brake wear reduction vs. schedule (or other priority) to give the slowing for and then re-acceleration from slow orders for a given consist? I know the stuff I was working on in the '80s did.
I would go for somewhere in between. Use dynamics to slow the train down as you approach. Air if neccesary, but most likely not needed.
To my knowledge, which is not complete, LEADER and Trip Optimizer do not have Temporary Slow orders in their data base of the subdivisions they are used on. Engineers still have to make the operating decisions for those actions.
Generally, if as line gets hit with 10 MPH Slow Orders, they tend to have more than one at a time - the relationsip of the Slow Orders to each other can have a consequence on how a train is operated. If two 10 MPH slow orders are three miles apart and you are operating a 10K foot train - what is the benefit of attempting to accelerate and then brake in the mile between where your rear end clears one slow order and your head end encounters the next.
In flat corn filed country where the normal track speed I would guess to be about 45 mph, would dynamics normally be enough to get the job done? How much does inertia and gravity play into slowing down? If the power was suddenly cut out or turned down drastically, does the weight of the train make it tend to start slowing to a stop, or does the inertia make it want to keep moving?
Uphill, downhill or level - all affect the movement.
You eye may not be able to detect the grade - the inertia of the train will.
Today’s Extended Range Dynamic braking is fully able to control territory such as you are describing.
I routinely use dynamics to hold our Christmas trains in the 12-15 MPH range on the way back down the hill from the “North Pole.”
An example of great engineer control of a train occurred here the other day. His IM train came down the grade approaching the siding signal showing approach, The siding has a sag in the middle Coming down grade he knocked off the dynamics and the train slowed in the sag until it was going "double low girl walking speed ". Continued to slow ntil a flat wheel thumped about every 10 seconds as the train continued to slow and finally stopped with what can only assume loco brakes only.
Once siding was occupied by north bound train he smoothly started the train with only a little slack running out.
Both LEADER and Trip Optimizer have temporary restrictions within their data base. If the systems are in use, it will slow down for the restriction and speed back up once clear. That being said, I wouldn’t expect BNSF has either in place on the track going by Murphy.
Throttle modulation first, dynamics second, air brakes third is the order the railroads like to see for controlling speed.
For Murphy’s situation, I’d just ease off, using the lay of the land first. Even what seems flat usually has some slight undulat
Jeff, are there any old heads out there who can regale you with stories of getting the trains over the road without dynamic brakes? Until the SD40-2s arrived, CNW didn’t use dynamics–to the point of having them removed from CGW and other secondhand units.
I’ve heard a few stories. Most of those old heads are retired now. Speaking of old heads, I’ve even met a few members of the Century Club. Members are those who were on trains that reached, or slightly exceeded, 100 mph. The ones that I knew were riding TOFC trains.
The original CNW SD-45 units without dynamics sure look different from everyone else’s SD-45 units.
Jeff
Can someone explain Leader and Trip Optimizer please? I’m perceiving it as a computer system that nags you…er suggests you how to operate your train for optimum fuel mileage(?) I picture it like the talking feature on a GPS phone app. “In 300 feet, turn right into the treeless ravine”.
When I would receive a train with dynamics I would consider it a luxury, and would look forward to the trip. Those dash2’s were so nice compared with all the old power.
The CNW SD40-2’s (6801-6925) had dynamics, fridge, electric baseboard heaters, and good seals around the doors; plus they were extremely dependable and predictable. And with ‘light engines’ they had a ‘0 to 60’ time of about 30 seconds!
Whereas the old power had none of that; even worse, the old units had an ice chest that you had to lug bags of ice to fill, plus the ice box was a heavy, solid metal-frame box with sharp edges, and was a lethal object in the cab in the event of a roll-over.
The worst thing about the SD50 was the extremely small toilet compartment–suitable in size for maybe a nice cat litter box, but just about useless for anyone over 120#.
LEADER comes in two forms. The first was engineer assist, where it prompts the engineer to change throttle or dynamic brake positions. It will also prompt to set or release air brake applications. It works better with empty unit trains or smaller manifests. I won’t follow it’s prompts at certain locations. It seems to always be calculating and reacting to where it’s at and where it’s going to be. This results on some downgrades in the prompting going back and forth between power and dynamics, when it should get into and stay in dynamics. I followed the prompts one time and LEADER did the nearly impossible, caused a DPU coal train to break into two pieces. (Many train separations have been caused by engineers following the prompts, especially on some of the land barges they like to run.)
The second version is auto throttle. Tha
It sounds like the systems amount to prompts to tell the engineer how to handle the throttle and brakes but it’s up to the engineer whether he/she follows it to a T? I can comprehend how information about the track dynamics could be preset in the system. How is the information about locomotives used, train length, train weight, etc. get input into the system? If one of the locomotives has issues do all the prompts become useless?
All that stuff is pulled from the computer system. When a train is built it’s all entered in and leader/TO pulls it from that. Changed can be amde enroute if needed.
You can select which engines are running, or not, as well.
Does an engineer get yelped at for not following the prompts? At the time by the system, or later by a higher up?
The system allows 14 seconds to comply with a prompt. (The prompt is both visual and audible. Although the audible alert sometimes doesn’t work.) The system makes a record and a manager later coaches the engineer. Unless the engineer had a good reason for ignoring the prompt and filled out an electronic EMS feedback/defect form. Not following the prompts too many times without good reason leads to discipline, for failure to comply with instructions. At least that’s how it’s handled where I work.
As Zug said, the train info is downloaded when logging on. We’re to edit the computer consist to reflect our paperwork. Usually, just minor differences. And we edit the consist after making setouts and/or pickups. If editing results in numbers over 10% different from the original consist, the system sometimes won’t work and will call for manual control.
Jeff