Would the Drag Wag the Wag?

[8wheels]

I’m after some advice about loading a wag and drag.

Currently I’m running a Scania 8x2 beavertail hiab, for plant and materials. One of the jobs that I do is to move 14t excavators which will see me run at max weight.

Now we are looking at replacing the truck, it seems that getting a 15.5t payload with a crane that can lift containers is just not possible anymore. If we downsize the crane it’s not worth having, it generates a lot of work and ideally could be bigger, if we go like for like we can’t move our 14 tonners on it. We have a lowloader so it’s not a huge problem.

My thoughts are to increase the crane size to attract more work and add a triaxle drawbar trailer to make a very flexible vehicle that I believe would be very beneficial.

Now if we have a new truck weighing around 18t and a trailer weighing around 5t would it be an option to load a 14t excavator on the trailer when the truck was otherwise unladen? The truck is 12m long and the trailer would be around 6m so I think that this would be OK? Or would it be advisable to load the truck with some ballast weights?

Also if we STGO plated it could we run the rigid at design weights (36-37t) when running with the trailer?

I’ve not worked with a drag before so welcome your thoughts,

[carryfast]

8wheels:
I’m after some advice about loading a wag and drag.

Currently I’m running a Scania 8x2 beavertail hiab, for plant and materials. One of the jobs that I do is to move 14t excavators which will see me run at max weight.

Now we are looking at replacing the truck, it seems that getting a 15.5t payload with a crane that can lift containers is just not possible anymore. If we downsize the crane it’s not worth having, it generates a lot of work and ideally could be bigger, if we go like for like we can’t move our 14 tonners on it. We have a lowloader so it’s not a huge problem.

My thoughts are to increase the crane size to attract more work and add a triaxle drawbar trailer to make a very flexible vehicle that I believe would be very beneficial.

Now if we have a new truck weighing around 18t and a trailer weighing around 5t would it be an option to load a 14t excavator on the trailer when the truck was otherwise unladen? The truck is 12m long and the trailer would be around 6m so I think that this would be OK? Or would it be advisable to load the truck with some ballast weights?

Also if we STGO plated it could we run the rigid at design weights (36-37t) when running with the trailer?

I’ve not worked with a drag before so welcome your thoughts,

Use an A frame drawbar trailer weight mismatch is then virtually irrelevant.
It’s how the Swedes manage to pull an around 40t gross trailer with a 25t gross prime mover.
Would it be better to go for a shorter 3 axle rigid and a 4 axle drawbar trailer ?.
Can only find a silly model pic but this configuration is a common routine sight in places like Switzerland for example.
flickr.com/photos/madphysicist/11904003664/

[adam277]

Firstly, No idea.
But I’ll comment just to give you my thoughts.
I drove a A-frame wag and drag for tuffnells so slightly different.

The issue you will probably have is that your running a 8x2 with a pretty small trailer. (compared to your rigid).
What that means is reversing it will be a pain. It will jack knife very easily when reversing. (I posted another another image as reference)
Generally speaking, the bigger the trailer the easier it is to reverse.

As for weights. I have driven a fully laden A-frame trailer with an empty rigid with no issues. But then again they have that extra front axle so may be more stable.

[juddian]

It’s not ideal, but your prime mover is a lot more substantial and longer than the trailer, we assume the trailer will have three fixed axles not an A frame design.

Handling wise from my experience of wag n drags (mostly with trailers as long or longer than the prime mover), driven sensibly this should be OK, but no doubt a swing could be set up if you provoked it hard enough or had the machine too far back on the trailer however you don’t sound the type to allow clowns out in your motors, no doubt you’ll experiment with placement of the machine on the trailer and find an ideal point resulting in the best weighting and most stable handling.

Haven’t a clue about special types requirements.

[acorn]

Also if we STGO plated it could we run the rigid at design weights (36-37t) when running with the trailer?

Unless you are running under STGO and the STGO criteria and all the pros & cons that comes with, you would be under normal weights. From your description of your loads, apart from your convenience, how would you justify that you can’t run it as a split load under C&U regs?

[8wheels]

I’m under no illusions that this is not going to be an easy outfit to get about with (but that sort of appeals to me oddly), I realise that it’s not going to work in all situations but it gives us the flexibility to use it where it suits or leave it at the yard if it doesn’t.

Realistically I can imagine there will be times where the trailer would be dropped in a better place and loads transhipped off the truck. There is no precedent to follow here for us so it’d be make it up as we go along. It would be a centre balance rather than an a frame and if a 14t excavator were to be loaded on it it would end up fairly well balanced. It’s buckets would be carried on the rigid, on one of our rigid only deliveries because an access is tight it could be hopped up on the truck outside and shunted in.

As for the STGO question, it was just an idea if the heavy trailer option was going to cause a problem. Thinking about it, it wouldn’t be allowed as the load has to be indivisible (so that bit works) and has to put the vehicle (or combination) over the C+U GVW of 44t which it wouldn’t. It was just a random thought, and I can’t imagine the boss paying for 2 STGO plates.

If this actually happens, I’ll be the driver and I’d imagine that when I’m on holiday it will not be used with the drag. It’s hard enough trying to find cover as it is so I can’t see them adding to the potential problems of having someone who doesn’t fully understand it in charge of it.

This could be the worst idea I’ve ever had, but I can see how this could be very useful if I can work out how to use it properly!

[punchy_dan]

I don’t think stgo can be used on a rigid because a bigger outfit can be used within c & u regs as in an artic ,as for reversing it I wouldn’t think it be any different to another rigid & trailer in fact 8 leggers are not known for good lock / turning circle ,Carryfast will tell you better than me anyway the thing with reversing is you have to get it right first time with an 8 wheeler & trailer as there’s no chance of turning the steering to correct it like the artic men wearing out the lorry through inadequacy .

[adam277]

If it makes financial sense go for it
There is quite a bit of flexibility in terms of using a trailer.
So financially sounds like you could be better off.

Heck you could even look at return loads like car pickups if you wanted to.

[mrginge]

energyhaulage.co.uk/haulage … wagon-drag

[wheel_nut]

Like we did with the caravan lorries and transporters, you can always load/hiab the trailer onto the rigid when done with it, look at the road planing men, they tug a road planer around on a trailer behind an empty tipper truck.

Sent from my iPhone using Tapatalk

[punchy_dan]

The beaver tail will be the problem preventing getting some angle on and the hitch will have to be right at the back rather than underslung meaning a short draw bar to keep overall length down but restricting the turn angle .my hitch is at the back of the chassis but being a roro the body overhangs by 4 ft and I’ve the standard 80 inch neck rather than cut down neck like others who’s trailers I can’t pull because the headboard will catch my body but they can’t pull my trailer as it puts them over length .

[punchy_dan]

The beauty is I can drop the body off completely with out dropping the trailer

[8wheels]

That’s roughly what is proposed albeit with a smaller crane. Because my work is roughly 50/50 own account / haulage this vehicle needs to be able to carry around 12t in it’s own right to continue much of the work that the existing one does.

Adding a trailer would give extra capacity, I have a job on Friday requiring two round trips of approx an hour hour each way that could be done in one hit. Ordinarily it’d go on the lowloader but it’s busy so I’m shuttling it.

As it stands currently we don’t have a lot of use for a wag and drag, but in the spirit of build it and they will come I think that if we have it we can find work for it. I’m certain that a number of our haulage customers would be interested in it’s potential.

As for STGO, I recall seeing a wag & drag on plates on one occasion so I think it can be done. But I’m struggling to think of what the circumstances could make using it within the letter of the law actually be.

Thanks for input, good to know that I’m not way off the mark with my idea.

[8wheels]

My plan has always been that the trailer could be lifted and piggybacked if required.

As you say Dan, the issue is with the hitch location, ideally it would be tucked under the tail. Andover trailers do a smart rising beavertail with fold flat ramps. The ramps can fold across the trailer allowing you load across the trailer or jacknife it round and bypass the trailer if space. This would be my preferred choice as I’ve ran Andover bodies for 15years and find them excellent, unfortunately the Andover option would take an eternity to get built and on the road.

MV Commercials build them for stock or to order on chassis that they have in stock so delivery times are much shorter, they offer a hydraulic beavertail which allows a hitch tucked underneath but has ramps that hydraulically slide out of the body. I’m not sure that they would be robust enough for what we have in mind and as this will likely be a 10 year vehicle longevity is key.

They do also offer a standard beavertail with rear hitch, which is the route we’d be looking at. Whilst this is not maybe the most user friendly configuration it’s either that or not at all.

[old_john]

If your lorry is 12m and the trailer is 6m, that only leaves .75m for the drawbar. That seems pretty tight.
I don’t think it would be either comfortable or particularly stable If you have to put the hitch right at the back. It potentially gives the trailer an awful lot of leverage on the drawing vehicle. Not saying I know what the answer is, just pointing out what may be the pitfalls.
Through gritted teeth I have to agree that the resident TN consultant engineer may be correct in this case when he suggests using an A frame trailer. They are much more inherentlystable, and have much less influence on the drawing vehicle.

[old_john]

Punchy Dan:
0
The beauty is I can drop the body off completely with out dropping the trailer

You’re such a smart esra Dan!!

Nice BTD 8 though. I know it’s got to be the last thing that would ever wear out, but if you know anyone who needs the big cast iron front gate in front of radiator, I’m your man.

[carryfast]

Old John:
Through gritted teeth I have to agree that the resident TN consultant engineer may be correct in this case when he suggests using an A frame trailer. They are much more inherentlystable, and have much less influence on the drawing vehicle.

You know it makes sense.No wagging happening here.Proper wagon and drag.
youtube.com/watch?v=AJi-BLNTKZU

[carryfast]

Or even 2 + 4.
youtube.com/watch?v=MnWHEoNAO0I 6.16 -

[mick_bracewell]

8wheels:
I’m after some advice about loading a wag and drag.

Currently I’m running a Scania 8x2 beavertail hiab, for plant and materials. One of the jobs that I do is to move 14t excavators which will see me run at max weight.

Now we are looking at replacing the truck, it seems that getting a 15.5t payload with a crane that can lift containers is just not possible anymore. If we downsize the crane it’s not worth having, it generates a lot of work and ideally could be bigger, if we go like for like we can’t move our 14 tonners on it. We have a lowloader so it’s not a huge problem.

My thoughts are to increase the crane size to attract more work and add a triaxle drawbar trailer to make a very flexible vehicle that I believe would be very beneficial.

Now if we have a new truck weighing around 18t and a trailer weighing around 5t would it be an option to load a 14t excavator on the trailer when the truck was otherwise unladen? The truck is 12m long and the trailer would be around 6m so I think that this would be OK? Or would it be advisable to load the truck with some ballast weights?

Also if we STGO plated it could we run the rigid at design weights (36-37t) when running with the trailer?

I’ve not worked with a drag before so welcome your thoughts,

How much is a 14t digger going to put you over on a new outfit? I can’t see it being much given that from what you’ve said it’s presumably doable with your current setup. Rather than looking at complicated solutions stick with the basics. Eg. are you running steelies all round or alloys? If the former, spec Durabrites. Over 10 rims you’ll save over half a ton there. Lose the light bars, michelin men, bullfighting spears get rid of your fridge and all the chocolate bars inside and go on a diet . 50kg saved there . What cab are you spec’ing? Scania are notoriously heavy. If you’re spec’ing an R series cab and/or with sleeper and/or high roof then you’ll easily be losing 0.5 to 1t of payload right there. We have P410 XT construction spec on our 8 wheelers (B8x2*6) with the CP17N cabs and we have a payload of 19825kg (steelies all round btw).

The Andover body might well be your preferred option, but how much is all the fancy split-folding gubbins going to add to your tare? I bet it will be more than your traditional beaver tail ramps.

As for traction, Wheel Nut makes a good point about the road planers being pulled on a tri-axle drag behind an empty 8 wheeler tipper. Personally I wouldn’t be concerned about the handling too much - I think it will be just fine so long as you’re sensible and mindful that you’re tail-end heavy. Positioning the load to put a bit more weight on the hitch will help, but will require some experimentation to get the ‘feel’ just right from the driving seat. If you go too far forwards then your steering will go light if you’ve nothing on the prime mover, but this should be somewhat countered by the weight of the crane.

But I can’t help thinking you’re trying to solve this conundrum by trying to shoehorn a square peg into a round hole. Do you actually NEED an 8 wheeler at all? Could all your work be done with an artic and rear-steer low loader? Do you NEED to access the middle of every construction site or is that just for your/their convenience and you could still get the job done by offloading on the road and driving the plant into the site? The idea of dragging a trailer around with you might appeal to you right now as you see it as a challenge or whatever, but I’m fairly confident the novelty will quickly wear off when you find you have to disconnect and reconnect it at every drop in order to load/unload wheeled or tracked plant from the prime mover. A decent driver with a rear-steer trailer can get into 90% of the places an 8 wheeler rigid can.

[8wheels]

Currenty I drive an R420 8x2 running on 12 alloy wheels it has a single fuel tank and a retarder which is quite a heavy lump. The Andover body is thick steel, with a thick wooden floor it gets heavy use and after nearly 12 years of use it is still solid.

I have a Hydraulic winch and a 23t/m crane, I carry lots of different chains and straps, tools and maps. It’s a bit of a swiss army knife and can solve most problems. It weighs with me, fuel, my lunch box and stash of T bags 16500kg giving me a payload of 15500Kg

That is not not much for the 14t excavators which have 4 buckets, a quickhitch and when coming back from site a trackframe that is rammed full of mud, baked solid or frozen in whatever.

I’ve looked for last couple of years at similar spec vehicles that are newer, every one I have found has been a tonne heavier at the point of sale without me adding my stuff to the mix, and that includes lesser specced vehicles on 10 wheels with lesser bodies

We have a rear steer step frame lowloader plated to CAT2, it carries our bigger plant and will likely take over the 14 tonners that I move. We have a very good driver on it who can get it in places that the relief driver (me) struggles to but there is also a fair amount of jobs that would not be practical for it, I do quite a lot of site clearance and movement works, paddling through the site to get to a container or materials of broken down plant to lift on. This is where the rigid is the most useful thing, we used to run a six wheeler but with a smaller crane and lesser payload it was less useful and tricky to load without overloading the front axle.

So an 8 wheeler is the thing for us, as for the trailer I know it will be a headache but it will not be a everyday thing however it will allow us to move our bigger plant if required if suitable to support the low loader which might be engaged it other work or save us having to cross paths to do jobs where the other truck has just been. We move quite a lot of tower lights for a local compamy, I can currently self load 5 and tow one, the low loader can carry 8 but needs a machine to load or unload, with a trailer we’d be increasing to 8 maybe 9 and still self load unload. There are other instances where it would be useful, 2x containers at a time, more site materials meaning less moves.

As for the length it would be approx 6m just used that as a reference, it would be put together by people who know far more than I do