I followed a green army car transporter onto the motorway earlier. Thinking he was doing a couple of local deliveries, and with the next junction being only a mile and a bit away, I didn’t take much notice - until he carried on for the next 15 or so miles and maybe further. There were four Transit Connect size vans on the trailer and absolutely nothing at all on the tractor. Even allowing for the high unladen weight of a car transporter and the relatively modest payload on the trailer it still seemed to look like the tail would be wagging the dog.
So what do those who know about these vehicles think?
cav551:
I followed a green army car transporter onto the motorway earlier. Thinking he was doing a couple of local deliveries, and with the next junction being only a mile and a bit away, I didn’t take much notice - until he carried on for the next 15 or so miles and maybe further. There were four Transit Connect size vans on the trailer and absolutely nothing at all on the tractor. Even allowing for the high unladen weight of a car transporter and the relatively modest payload on the trailer it still seemed to look like the tail would be wagging the dog.
So what do those who know about these vehicles think?
Car transporter outfits can vary in design to the point where the coupling point relative to the prime mover rear axle/s means that they can often be seen as being almost more like a dromedary type artic.Rather than rigid and close coupled trailer in the accepted sense.On that note the former type probably wouldn’t be as critical regards weight mismatch as a normal rigid with the usual type of rear over hang and coupling position.Which can probably also be seen in the fully laden situation of relatively few vehicles on the prime mover v a much bigger load on the trailer.IE a few on the trailer and none on the prime mover would probably be no different to the mismatch of a full load on both in that regard depending on design.
While assuming that isn’t the case it would then just be a case of calculating the exact mismatch which applied in terms of trailer unladen + load v prime mover unladen.Probably not enough to have bothered the driver in this case ?.
I did the job for many years and i’ve actually seen one brain donor with 4 x Discovery 3’s (2.7 tons each) on the trailer (incl the rear two right on the arse end) and bugger all on the prime mover, talk about tail wagging the dog.
The load in question isn’t much in terms of weight, but i wouldn’t have done it unless A it was bone dry and B i was only going a short distance, you could mitigate the problem by siting two of the vans at the front of the trailer and the next two immediately behind them, thereby transferring as much weight as possible onto the towing hitch.
I’d have put one on the prime mover behind the cab, one up one down front of trailer and one just behind the lower, vehicle would have driven well and been post height, 13’ 3".
If you had only one reasonably weighted vehicle on the combination and put it right on the back of the trailer you can tell immediately.
It helps if the vehicle is EHR bodied, as Lohr types have a semi circular stabiliser built in behind the hitch, you can hear the friction shoes grinding as the vehicle turns corners, Transporter Engineering bodies have no such device and can prove a handful unless you load sensibly.
The first time you get to drive one of these designs is an eye opener, the first time you drive one immediately after its had a new set of drive axle tyres is a revelation…my mate once described it as trying to drive a plate of spaguetti, about the most apt description i’ve heard.
2 key factors that never really get mention when people refer to tail wagging the dog are wheel base as in longer the better and drive axle weight ,I’ve done a few loads with midlift rigid with axle up rear crane weighing 3.5 tonne empty lorry 13 tonne and trailer weighing 14 tonne which drives fine .Anyone know the max weight to be imposed on the drawbar coupling on these car transporters where the trailer wheels are set at the back ?
Juddian:
I did the job for many years and i’ve actually seen one brain donor with 4 x Discovery 3’s (2.7 tons each) on the trailer (incl the rear two right on the arse end) and bugger all on the prime mover, talk about tail wagging the dog.
The load in question isn’t much in terms of weight, but i wouldn’t have done it unless A it was bone dry and B i was only going a short distance, you could mitigate the problem by siting two of the vans at the front of the trailer and the next two immediately behind them, thereby transferring as much weight as possible onto the towing hitch.
I’d have put one on the prime mover behind the cab, one up one down front of trailer and one just behind the lower, vehicle would have driven well and been post height, 13’ 3".
If you had only one reasonably weighted vehicle on the combination and put it right on the back of the trailer you can tell immediately.
It helps if the vehicle is EHR bodied, as Lohr types have a semi circular stabiliser built in behind the hitch, you can hear the friction shoes grinding as the vehicle turns corners, Transporter Engineering bodies have no such device and can prove a handful unless you load sensibly.
The first time you get to drive one of these designs is an eye opener, the first time you drive one immediately after its had a new set of drive axle tyres is a revelation…my mate once described it as trying to drive a plate of spaguetti, about the most apt description i’ve heard.
The inherent payload ‘weight distribution’ issues/flaws of whatever type of close coupled design aren’t the same thing as just the issue of weight mismatch between trailer and prime mover overall.IE try that type of overall mismatch with an ordinary type rigid and close coupled trailer. 
woma.co.uk/medialibrary/_Ful … porter.jpg
c1.staticflickr.com/9/8430/7751 … 6af9_b.jpg
IE those outfits would arguably be more along the lines of the dromedary artic combination in terms of overall weight relationship between prime mover and trailer and its handling than usually accepted rigid and close coupled trailer.
Or if not in view of your description possibly a predictable combination of the worst aspects of both.IE the car transporter scene seems to be a case of trying to use and to make a rigid and close coupled trailer act as an artic. 
if your talking about the small connect vans then there’s no problem, I had probably one of the first 10 of the 11 plus, and it never felt unsafe with whatever load was on it, don’t know where the weight of a disco comes from but they were nowhere near 2700kg, more like 2200kg.
The problem with the design is that the prime mover is a simple tractor unit, but the trailer hitch is behind the drive axle.
Loaded well and driven with respect for the design they’re fine, load them badly and/or throw them about, especially in the wet, and its just a matter of time.
If you carried Disco 3 for export the weights are stated on the paperwork, Diesel 3’s approx 2.7 tons same as Sport, RR’s were a little lighter having an integral chassis.
Edit, quick back of ■■■ packet adding up, got pulled at Risby for check weighing, gross over 42 tons, tare 22500, 6 Disco 3’s 1 Defender @ under 2 tons, work it out yourself.
Juddian:
The problem with the design is that the prime mover is a simple tractor unit, but the trailer hitch is behind the drive axle.
Realistically it should either be viewed as artic or a drawbar outfit there’s no way of trying to mix both.In which case as usual the latter would be more stable in the A frame configuration than close coupled.
Carryfast:
Juddian:
The problem with the design is that the prime mover is a simple tractor unit, but the trailer hitch is behind the drive axle.
Realistically it should either be viewed as artic or a drawbar outfit there’s no way of trying to mix both.In which case as usual the latter would be more stable in the A frame configuration than close coupled.
For years i drove the older designs (much preferred), full length rigid lorry prime mover, 2 or 3 axles, with a centre balanced 2 or 3 axle trailer, these designs were brilliant for stability, PM being well in control unless you really cocked it up.
Not as simple for tractor renewal though, with the current design its a very straigforward job dropping the old body onto a new tractor, big job doing the same with a full length rigid…then what do you do with the used lorry, stick a 5th wheel on and its a standard tractor overnight, who wants a rigid bare chassis?
Often see 3.5t Sprinter transporters unladen towing a trailer with something like an A6 Audi or a Disco on it.
At 70 mph
It’s alright for them, I guess but def not my idea of good practice and I wouldn’t be entertaining it.
Ah, here’s Matron…
Juddian:
Carryfast:
Juddian:
The problem with the design is that the prime mover is a simple tractor unit, but the trailer hitch is behind the drive axle.
Realistically it should either be viewed as artic or a drawbar outfit there’s no way of trying to mix both.In which case as usual the latter would be more stable in the A frame configuration than close coupled.
For years i drove the older designs (much preferred), full length rigid lorry prime mover, 2 or 3 axles, with a centre balanced 2 or 3 axle trailer, these designs were brilliant for stability, PM being well in control unless you really cocked it up.
Not as simple for tractor renewal though, with the current design its a very straigforward job dropping the old body onto a new tractor, big job doing the same with a full length rigid…then what do you do with the used lorry, stick a 5th wheel on and its a standard tractor overnight, who wants a rigid bare chassis?
I was referring to this type of configuration.It’s just a case then of bringing that up to date in the form of the short wheelbase tractor unit based rigid and a longer A frame trailer.
viewtopic.php?f=28&t=28722&start=150#p1393946
I think the Transit Connect is surprisingly thirsty, you can get just as good mpg from a larger van,
