switchlogic:
Wheel Nut:
pete smith:
You could try Mac’s Truck sales and see if they could advise you or put you in touch with a past customer of theirs, only seen their adverts for plant wagons and have had no dealing with them in the past.
I run 8 wheel hook loaders with tandem axle close coupled trailers and have in the past run with an empty bin on the unit and the trailer at full wack, 18 ton, and it was not a problem and have done it on numerous occasions. The unit would be grossing around 17.700 kgs and the trailer at its plated weight of 18,000 kgs. Sorry I cannot be more helpful
You havent been listening, a tandem axle close coupled trailer is for fools and failed coach drivers! 
0
I’m not sure I can be trusted with such a fancy trolly
Bloody hell wheelnut that is a rear steer so we’re in for a lecture on those and probably the British Railways BRUTE trolleys
pete smith:
8wheels:
OK some interesting points raised, but there are still some issues that I have.
The bulk of the work for the intended vehicle would be rigid only, drag would not be in constant use so that calls for a 12m long rigid to maximise it’s potential. There are many of our jobs where just getting a rigid in is possible but getting a trailer in too would not be, a shorter rigid would mean less load capacity. Yes the trailer could be longer but that wouldn’t help.
The empty rigid would be somewhere in region of 18-20t, trailer could theoretically be 24t but would be operating at around 20t with a 14t excavator on it. Buckets, and or other attachments for the excavator or a dumper could be carried on the rigid altering the weight balance. That was the original question asked and from the drivers who have responded with experience it would seem that this is not going to be a big cause for concern, the weight and length of the wag is significant enough to counter the effect of the drag.
Availability is another factor, unfortunately we are not in a good position time wise. Having a Euro IV truck so close to the impending ULEZ is not viable, I know this should have been sorted long ago but the initial soundings on replacing the vehicle hit a block with trying to find a way to build a comparible spec vehicle to the current one and failing. Searching for a built and ready example was also fruitless, i’m sure there was some hope that something would appear magically like it did 10 years ago when we bought the current vehicle.
CoVid happened and we spent a pretty bad shutting up shop, all the plant was off hire and getting parked up. I left in March not knowing if I’d be going back or if I did how long we’d be able to survive. Things picked up a bit and the company streamlined and downsized to get in a better position, the clock had rolled on and now the situation was more sensitive. Getting exactly a vehicle built to spec with everything to our / my / ideal spec from chassis to crane to body would take far too long. We are now looking at options that are available from a supplier who builds for stock or has chassis and cranes available and a selection of options for bodies so you can get a vehicle specced how you want it much quicker. They also supply rental vehicles of a similar spec that can be used as an infill.
Lastly there is is the issue of drivers. There is myself, my colleague who drives the lowloader and one of our young machine drivers who has a little expereince of driving the low loader. This vehicle combination would be my long term and only require someone else to drive if I was on holiday or was off sick (never had a day off yet) The current vehicle is hard enough to find a competent willing driver for (one driver can’t do the crane, the other doesn’t want to as not really current and hates driving a rigid) With the intened spec it could be left as a rigid only and still carry out most of it’s duties. Making it shorter with a longer trailer and therefore an outfit that worked together more often than not would be difficult to find cover for unless you used it as a shorter less useful rigid.
Regardless of whether the trailer comes or not, the vehicle will be more or less the same. If after a couple of years and it proved to be something that wasn’t working, ditching (not literally) the trailer could be considered. It could be sold and the vehicle operated as rigid only, as it would be exactly the same except for the coupling as I’d spec anyway.
Whilst I appreciate there may be some merit to your solution, I don’t believe it is the answer in this particular set of circumstances.
You could try Mac’s Truck sales and see if they could advise you or put you in touch with a past customer of theirs, only seen their adverts for plant wagons and have had no dealing with them in the past.
I run 8 wheel hook loaders with tandem axle close coupled trailers and have in the past run with an empty bin on the unit and the trailer at full wack, 18 ton, and it was not a problem and have done it on numerous occasions. The unit would be grossing around 17.700 kgs and the trailer at its plated weight of 18,000 kgs. Sorry I cannot be more helpful
Thanks for the confirm of what I need Pete, another actual user telling me that what I have in mind is do-able and not likely to give me serious issues.
Given free reign with the funds and time, it would be coming from Andover who build a very good spec usable outfit but would require lengthy delays to source all the bits. Coming to suppliers with ready availability leads us to Macs who we have spoken to and MV commercials. MV are the preferred choice, their spec seems to fit the bill well and it would seem that all dealing with them are efficient and straightforward. I’ve studied the drawings for the body and made suggestions about how to tailor it to how I would like it set up. Nothing seems too much for them and no obstacles or problems. They can also supply a vehicle in the interim.
I am not the one to push the button on final order so final say is not mine, but I’ve had a large part in getting the spec drawn up. I think it’s going to happen, then it’s down to them to get the work and me to do it
adam277:
The issue with the A-frames is they are just a complete pain in the ■■■ to reverse.
I dont care how good you are at reversing A-frames. Just trying reverse 100-200 yards in a straight line can be a complete pain.
I like A-frame trailers in general they are nice to drive. But that is one of the main reasons they are not popular.
‘Good’ by definition means no longer a ‘complete pain’ reversing it anywhere it’s just instinctive like an artic.
They both have the ability to make anyone look like a novice at the start and sometimes just on the wrong day or after getting back after a long holiday. 
I was surprised/shocked by that old WW2 REME training video in that regard.
Practicing putting them under a demount box especially from 90 degrees bonus points ‘blind side’ will soon sharpen up the reflexes and sort out any fears in that regard.If not some decent challenging cone and post layouts in the yard.
Straight line is just simply applying very controlled well timed, if any, steering inputs to keep the corners together in the mirrors.No one said it can/needs to be done at 10-15 mph backwards.
As stated those inputs need to be instinctive.
Which leaves the question what is this Brit phobia all about in that regard v our foreign counterparts from Scandinavia to New Zealand.They wouldn’t even be discussing it and certainly wouldn’t describe them as a pain to put anywhere that they need to.To the point of being the default C + E training vehicle of choice in many places.
pete smith:
The unit would be grossing around 17.700 kgs and the trailer at its plated weight of 18,000 kgs. Sorry I cannot be more helpful
What’s the tare weight of the tandem axle trailer ?.
Also don’t know the exact weight distribution of the load over the trailer which the OP was describing.
If the OP was only ever intending to match the more or less tare weight of the prime mover with the gross weight of the trailer why would he have been worried about the tail wagging the dog.
My bet is in the real world a large excavator on a close coupled trailer v an empty/light loaded rigid of whatever type is going to be a bit of a handful especially downhill.
But taking the numbers at face value don’t really understand why the OP is that bothered about any actual significant prime mover/trailer weight mismatch.
I thought he meant downsizing the prime mover in favour of maximising trailer capacity because of the diminishing returns of the increasing tare weights of rigids.
The trailer weighs I believe around 5t, the 14t excavator has a track frame / footprint of around 3.5m. I’ve never measure it, but guessing around that, some of the machines have a counterweight that overhangs the tracks at the back and the zero swing models do not so they would balance differently. The arm of the machine when folded for transport projects from the machine but if the track frame was central over the axles the projection would not be extreme. Furthermore the machine could travel facing forwards or backwards if it helped find the sweet spot for balance.
Thinking about it, there is a company who spread sewage cake in fields put a 14t on a triaxle behind a tipper which must run empty. That outfit would be shorter and lighter at the front and they obviously manage OK.
It was never about maximising the tare of the rigid, always about enhancing the capabilites of the vehicle as a standalone and not forgoing a capability that has become increasingly useful.
I asked the question about wagging as I’d heard about it but didn’t know exactly at what point it could be an issue. I was 90% sure that I was on the right track but seeking confirmation that I wasn’t about to do something that was an obvious no no
A bit of a thread resurrection but at the risk of waking Carryfast and the a frame monster, I thought I would update on the original post.
Many thanks to everyone who had input in answer to my questions, I was fairly confident I was on to a good concept but wanted some reassurances that this wasn’t going to be a big mistake.
Vehicle was ordered last year and finally was completed and on the road in late December. First ever day driving a wag and drag was straight out from base up to Darsham Suffolk for 2x 21’ containers to Oxford, and unload at 1700 in pitch dark.
So far it has proved to be a useful tool, having the flexibility to supplement our stepframe Lowloader has proved invaluable and on more than one occasion has saved the day when otherwise a job would have been cancelled or postponed. Whilst not out every day (drag) or even all day it’s probably out for about 30-40% of the time the truck is working.
It’s been a learning curve but it has surprised me how easy it is to use and operate. To date only one job has required me to split the combination and load separately. I’ve managed to access sites that I would struggle with the lowloader.
I’ve found that the quality of the road makes a big difference to the way it drives but in answer to original question the drag does not wag the drag when loaded heavy with no weight carried on the truck.
Sorry about the sideways pictures but I’m a technotwat and can’t manage to sort that out.
Very nice outfit that ,I’am about 18/20 months behind you although I’ve got the crane ,and paid the deposit on an 8 wheeler fh540 low roof
switchlogic:
Carryfast:
I have absolutely no experience whatsoever of ever putting a artic in a ditch and almost getting it on its side so you’ve at least trumped me in that regard.I’m guessing no thanks from the guvnor for your safe driving there.If it had been UPS they probably would have passed on the 3 avoidables allowance in that case and cut to the chase of summary dismissal. 
Just in case anyone is wondering what the forum fool is talking about
lorry-driver.com/search?q=N80&m=1
One of the more, errrr, interesting days of my eventful career
0
Wouldn’t worry to much Switch - the man that never had an accident never did much
8wheels:
A bit of a thread resurrection but at the risk of waking Carryfast and the a frame monster, I thought I would update on the original post.
Many thanks to everyone who had input in answer to my questions, I was fairly confident I was on to a good concept but wanted some reassurances that this wasn’t going to be a big mistake.
Vehicle was ordered last year and finally was completed and on the road in late December. First ever day driving a wag and drag was straight out from base up to Darsham Suffolk for 2x 21’ containers to Oxford, and unload at 1700 in pitch dark.
So far it has proved to be a useful tool, having the flexibility to supplement our stepframe Lowloader has proved invaluable and on more than one occasion has saved the day when otherwise a job would have been cancelled or postponed. Whilst not out every day (drag) or even all day it’s probably out for about 30-40% of the time the truck is working.
It’s been a learning curve but it has surprised me how easy it is to use and operate. To date only one job has required me to split the combination and load separately. I’ve managed to access sites that I would struggle with the lowloader.
I’ve found that the quality of the road makes a big difference to the way it drives but in answer to original question the drag does not wag the drag when loaded heavy with no weight carried on the truck.
Sorry about the sideways pictures but I’m a technotwat and can’t manage to sort that out.
That looks like a useful outfit . I’m glad it works and drives how you wanted it to .
Punchy Dan:
01Very nice outfit that ,I’am about 18/20 months behind you although I’ve got the crane ,and paid the deposit on an 8 wheeler fh540 low roof
It’ll be nice then, I quite like the low roof cabs. Still lots of space inside but not bashing every low branch down the country roads. I’d have quite liked a 540 but availability was key for us and the 460 manages our relatively flat bit of the country well enough.
Overall I’m pleased with the setup, the truck body is not as good for doing plant work as my previous vehicles I find that the hydraulic beavertail is a bit steep. However it is quite powerful and if a machine is struggling to climb up then you can lift the tail with the machine on.
Although it has been bought primarily for own account work moving our own plant it has been specced to be as flexible as possible so we can attract more third party haulage jobs.
8wheels:
Punchy Dan:
01Very nice outfit that ,I’am about 18/20 months behind you although I’ve got the crane ,and paid the deposit on an 8 wheeler fh540 low roof
It’ll be nice then, I quite like the low roof cabs. Still lots of space inside but not bashing every low branch down the country roads. I’d have quite liked a 540 but availability was key for us and the 460 manages our relatively flat bit of the country well enough.
Overall I’m pleased with the setup, the truck body is not as good for doing plant work as my previous vehicles I find that the hydraulic beavertail is a bit steep. However it is quite powerful and if a machine is struggling to climb up then you can lift the tail with the machine on.
Although it has been bought primarily for own account work moving our own plant it has been specced to be as flexible as possible so we can attract more third party haulage jobs.
I’ve ordered front air suspension with maximum stiffness roll bars set up ,what size is your crane ?
It’s a 36t/m with 12.8m reach on front springs. It’s a bit finicky and doesn’t like lifting round towards the cab, it needs a lot of adjustment on the legs to keep it level.
I had a similar truck on hire with a Hiab 418 on it, which was a much better unit.
Full rotation with rear leg beam and never gave me any dramas lifting anything anywhere.
The 36tm is good and lifts well enough but it can be tricky getting things in tight corners.
But other than that I’ve done quite well.
I sometimes get asked if I am Welsh.
No
Why is there a dragon on your trailer?
It’s just I’ve got my drag-on
It amuses me. Plus a nod to my son who has moved to Wales
