Thursday night my wife, who usually doesn’t pay much attention to trains, saw 4 moving grain trains while driving down about a 60 mile stretch of highway that parallels a BNSF line in south east Minnesota. She was surprised to see that many trains. I was surprised that they were spaced so closely. It’s fall, and the grain is moving big time in our part of the world.
On a normally busy freight route, how close can the trains be spaced? I realize that it’s a function of how long the blocks are, but on a busy line, with well oiled machinery, and some luck, just how close do they run them on a regular basis?
Often trains are spaced at 10 minute intervals supposedly. So if you are driving against the train traffic at say 60 MPH you should encounter a train every 5 minutes if the trains are coming at you at the same speed. So, yeah, it might appear that they are closer together than you might think If they are going in the same direction as you, and pass you more often than 10 minutes apart…they are going fast, very fast.
Norris, ask her whether the trains were moving. I understand that BNSF has been very clogged recently, due to both grain and oil business. Nice problem to have, if things can be kept moving.
Depends on how the line is signalled (I would assume it is).
Distance between signals, number of aspects until the signal goes green, stuff like that.
F’rinstance, if we assume that the block signals provide a two block safety buffer, and that the signals are located every two miles, then you’ll have a minumum of four miles between trains.
If everything is flowing smoothly and all the trains are running at the same speed, it’s possible that they are running “on the yellows” - getting to each signal just as it goes to clear, which would put the minimum possible distance between the leading and following trains.
Far too many variables for a signal novice like me to give a definite answer.
Carl- She said there were also a couple of trains “loading” at online elevators. Since most of those elevators load out with their own yard goats, and not full trains, I’d guess a couple of those were actually trains waiting in sidings.
IIRC, this is the ex-GN line from Wilmer, MN to Sioux City, IA with a branch over to Sioux Falls, SD. The last time I was out there there was NO block signals. It should be TWC territory. There are quite a few trains on the line.
In which case, it’s a function of how quickly trains can call clear of block stations, how far the block stations are apart, and how fast the DS and crews can read their track warrants over the radio…
Some railroads use radio blocking in dark TWC territory. I’ve only done it when detouring over the CN/IC and IAIS. Under radio blocking, the following train is instructed to not foul the limits of the leading train. Then the leading train reports to the following train when it is clear of certain identifiable points (usually a mile post) and then the following train can move up to that point. It minimizes dispatcher involvement.
Jeff, here’s a related question for you (which you may have answered before, but I’ve forgotten, as is befitting an old fa…mily man with a mind like a steel sieve):
Does ATC keep trains down to Restricting on an Advance Approach aspect? Had a stack train go through westbound, followed by an auto-rack train moving slowly enough, on a flashing yellow. Train ahead must have been slowing down for an eastbound scoot in a station with no tunnels.
Isn’t that “radio blocking” similar to what trains do/did in suburban territory? I’ve heard scoots announcing their departure from stations for the benefit of following trains (not so much now that block signals are in place on our lines here).
An Advance Approach will normally cause the ATC to drop to restricting. An exception is when the signal is in advance of a crossover move. We normally get two consecutive “flashers” when lined to crossover. Before they changed all the signals to approach-lit mode, you used to know you were crossing over before you went past the first signal, that is if you could see both. Now you wait until you go by the signal and wait for the cab signal to drop out.
There are three signal locations out around Missouri Valley that don’t give you train control on an Advance Approach no matter how you are lined up. The way it was explained to me was that originally when adding wayside signals and CTC, they first were going to have the ATC drop out only on an Approach, or less favorable than an Approach. Then they decided that it would be better to have it drop out on anything less favora