Red Line Train *Bangs*

Tonight I took an Ashmont train from Harvard to South Station (9:30-45). As we left about half the stops I heard a loud bang, but felt no vibration other than I would expect, nor did the train pause or slow. Admittedly an infrequent T user over 25 years, this was a first. I thought brakes, then I thought of slack letting out as a freight train starts. I was in the middle of the train.

If it was just a bang, then yes, it was slack caused by uneven acceleration. If it was a bang and then a twang, then it's the truck.

Thanks- I'm glad it's something I understand.

Also low airbags "suspension" can cause banging up and down, usually on the 15,16 and 1700s

Or the poorly ballasted track at Columbia Junction will do it too.

diburning wrote:Or the poorly ballasted track at Columbia Junction will do it too.

Is this the same one referred to as malfunction junction?

Wouldn't bad track make a vibration or rumble? For example, I heard a bang like hitting a metal trash can, but felt no different vibration. I hear every car, or every set of trucks bang through switches.

Also low airbags "suspension" can cause banging up and down, usually on the 15,16 and 1700s

Yes, it sure has, as Ive experienced those unusually loud "pop pop" sounds which have scared me sometimes assuming worse issues. Its also has happened even on the 01800s, too. When riding them as of recently, they've also made that "poppin'" sound

The breaking system is not train air so the operator cannot stretch or compress the cars like the CR does., yes the air bag suspension being too low could cause that and the other issue with the low air bag is if they are low can also cause the cars to bump and hit the platform when it arrives in the station. I will say from first hand knowledge when I would be with co workers on one of the rapid transit line and they had issues with the train and wanted it off the road one of the crew would cut out a cars brakes out when the train would arrive in to the station causing bucking and pushing the train a bit before they stopped half way down the platform the crew member cuts the break back in before they depart. They would call central and say braking problems or the train starter and get it switched off the road,

joshg1 wrote:Tonight I took an Ashmont train from Harvard to South Station (9:30-45). As we left about half the stops I heard a loud bang, but felt no vibration other than I would expect, nor did the train pause or slow. Admittedly an infrequent T user over 25 years, this was a first. I thought brakes, then I thought of slack letting out as a freight train starts. I was in the middle of the train.

Since it was happening specifically when accelerating from a stop, it was very likely slack in the drawbar/draftgear/coupler anchor assembly. This can happen from wear, or from mis-adjusted draftgear that is not taking up slack as it should. A good-condition drawbar assembly doesn't normally exhibit any banging.

If you experience this, take a peek at the lights on the side of the car when you get off. A blue or blue-green light(01800s) indicates a car with the propulsion disabled. Such cars take a beating during acceleration and braking. I have seen two dead cars in a six car train. Before you ask Red = "Door not Closed" and Yellow = "Snow Brake"