57 or 54, one of those 2. It says in the DS13sr decoder literature that some cv's including those in the 50's can be programmed but will be ignored so that would preclude the instant selection of switching speed mode. So you would have to stick with Digitrax decoders for that luxury of instant change to the switching speed mode.
Yes, most switchers were capable of faster speeds depending on the gear ratio applied - the lowest gearing on EMD units allowed 55 MPH but due to those hard riding AAR type A switcher trucks underneath the units most switchers were limited to 35 mph. You could go faster but you probably would have been shaken to death in doing so. If the switcher is a working trailing unit in consist with no crew on board a higher speed would be ok because the crew wouldn't get rattled around. You would just have to watch the max speed so the unit wasn't overloaded and burned up something in the somewhat primitive electrical systems, or the components thereof, of the time when they actually built units just as pure switchers for yard or light road service switching capability. If just towed along in consist idling and isolated or dead in tow then it wouldn't be an issue as to how fast it went other than it may shake something loose on the unit from vibration.
Interestingly and oddly enough- NC&StL and Alaska RR had GP7's , and perhaps other roads and/or other models, that were factory equipped riding on AAR type A switching trucks. I think that eventually they were probably changed out for the normal Blomberg road truck after enough crew complained about the rough ride or they found out it was hard to use them at other than lower road speeds- it would be akin to driving your vehicle with the shocks taken out.
Yes, most switchers were capable of faster speeds depending on the gear ratio applied - the lowest gearing on EMD units allowed 55 MPH but due to those hard riding AAR type A switcher trucks underneath the units most switchers were limited to 35 mph. You could go faster but you probably would have been shaken to death in doing so. If the switcher is a working trailing unit in consist with no crew on board a higher speed would be ok because the crew wouldn't get rattled around. You would just have to watch the max speed so the unit wasn't overloaded and burned up something in the somewhat primitive electrical systems, or the components thereof, of the time when they actually built units just as pure switchers for yard or light road service switching capability. If just towed along in consist idling and isolated or dead in tow then it wouldn't be an issue as to how fast it went other than it may shake something loose on the unit from vibration.
Interestingly and oddly enough- NC&StL and Alaska RR had GP7's , and perhaps other roads and/or other models, that were factory equipped riding on AAR type A switching trucks. I think that eventually they were probably changed out for the normal Blomberg road truck after enough crew complained about the rough ride or they found out it was hard to use them at other than lower road speeds- it would be akin to driving your vehicle with the shocks taken out.