Sorry if this is off-topic, someone in the know can message me if that’s more acceptable, but why is there a limit on how many units can work in multiple? Is it something to do with some systems operating between them or something else? Would be grateful to anyone know who’s
I thought it would be something to do with that, thank you!I believe it's due to signal degradation (although that might just be conjecture) as it travels through the couplers through the various units. Of course, if you lose electrical connectivity, you lose the ability to control any train(s) beyond that point.
I’m sure I read elsewhere that with BSI coupled units, so basically anything diesel between a Pacer and a Turbostar, there’s a max number of cabs that can be in the formation, I think it’s 8. As a result you can tie 4x153s together, but potentially 12x170s
Twelve cabs maximum in that case - but intermediate vehicles have to be counted as a cab for this purpose too. It’s down to voltage drop on the control circuits, as I understand it.I’m sure I read elsewhere that with BSI coupled units, so basically anything diesel between a Pacer and a Turbostar, there’s a max number of cabs that can be in the formation, I think it’s 8. As a result you can tie 4x153s together, but potentially 12x170s
Twelve cabs maximum in that case - but intermediate vehicles have to be counted as a cab for this purpose too. It’s down to voltage drop on the control circuits, as I understand it.
TPE have ran 9 car services before, albeit rare. Manchester when a Glasgow based football team was playing in Manchester (can’t remember the fixture) and the screen went down in Piccadilly gardens, masses of Scots decamped to any pub they could find showing the game but as many were staying overnight in Blackpool TPE ran a 9 car and 6 duplicate with the 9 not calling at occy road. The 6 car still left people behind!
I have also ran a 9 car via Calder valley although in that case rear 3 were locked out. Some sort of disruption positioning move can’t remember the details but saved a cancellation
Which is why it's better to think of vehicles rather than cabs because the centre car of 144s and 158s has caused confusion in the past over the number of units making up a train. A 153 counts as 2 vehicles for the sake of multiple working.
Not quite right, we used to regulary operate 13 car, sometimes 14, on boat trains from Victoria to Folkestone Harbour or Dover Marine, usually 3 x 4 CEP + 1 or 2 MLV. Sometimes it would be a CEP/BEP/CEP formation + the MLVOn the Southern Region , the limit was the 3rd rail current .
With 1950/1960 units 12-car was the limit e.g 3 x 4VEP or 6 x 2EPB
Only 2 Class 73's could MU in electric mode , 3 x 73 would blow the substation breakers.
the current index loading limit was 16 any more you cut out motorsNot quite right, we used to regulary operate 13 car, sometimes 14, on boat trains from Victoria to Folkestone Harbour or Dover Marine, usually 3 x 4 CEP + 1 or 2 MLV. Sometimes it would be a CEP/BEP/CEP formation + the MLV
Indeed at our place it was 12 vehicles if it was all 15x, if it was all 14x or a mixture or 14x and 15x it was 8 max. However a 153 counted as 2 vehicles. All to do with the signal through the electrical boxes on the coupler I believe
As I understood it 4CEP+1MLV was within the typical third rail index of 14.and I do state typical as not every route is powered equally. An EE507 is worth 1 but an EE546 was 1.5 so a 12CEP plus 1 MLV would be rated 14, REP+CEP would have an index of 16 and required motors to be isolated and I recall stories on this forum this has been done. 3x73=18 so definitely popping breakers unless running on diseasal. Sure it wasn’t a TLV coupled to the MLV?
It is possible however the boat train route had a higher index, especially once additional power was added for Eurostar, but by then the point in boat trains was lost...
the current index loading limit was 16 any more you cut out motors
a class 73=8units
a rep =14 or may be the full 16 cant remember
also you could have 2xmlv[motor luggage vans ] rather than an mlv and tlv[trailer luggage van] and a 12 on a boat train and not exceed the 16 limit
all other stock up until say pre 1990 are all 2 or 4 dependent on the number off traction motors but in general 1 per coach except as said above the reps and mlvs.
although i did train on the319s i cant remember what current limit they where as they had a bit more go in them.