Truck and pig into 19m

Hi Wedge...
This is a very interesting post to me.
In the dim and distant past I used to do many axle load, length and geometry calcs and then the laws got more complicated and restrictive and eventually in the early '80s Ford Trucks, supplied the UK dealers with a very primitive computer to do the calcs. It was not easy to use but it worked.
( I still did a manual calc to make sure when necessary.. )
I obviously did not get involved in the type of configuration you are discussing, as dogs and pigs are very different over here
This requires a very complicated multiple calculation :-

Steering geometry for towbar ( UK Gooseneck) on the pig and for the A Frame ( in the UK Dolly) on the Dog is just basic Pythagoras calculations, same the world over.

Weight Distribution is Oz specific.

Overall Length calculation also Oz specific.

But what is same the whole world over is that even if all the calculations are performed perfectly by a computer program or maths genius, there will still be that ONE hump bridge with an adverse camber or slope on one side, or loading ramp, which will cause a problem.
You can use all Swishys Cornflake boxes, the best programs going, but Sods law will catch up in the end.... and if Mr Sod doesn't, the man from the ministry will also have a go.

Making these dimensional decisions is a nightmare now, and all those involved in making them have my sympathy.

Of course I haven't mentioned calcs for performance, economy or running costs, which are also very important.

I would love to see the final decided setup and dimensions.

Cheers
RS

Yes Paul very helpful. So you guessed 7200 wheelbase then worked from there? That's a fairly long wheelbase, from what I remember looking at specs it might be the only truck out there that can go that long? I thought the bigger Western Stars were only short but I missed that the 4800fxc goes to 252" (6.4m), I thought it might almost be ok but you reckon we need heaps more... How did you come up with 7200? I need to sit down with a pen, paper, calculator and scissors and really go through this. Just don't have much of that sort of time at the moment, hopefully on wednesday...

Yep need a bullbar for sure, have them on everything and have prevented a lot of damage.

Who's this debo then?

Roland I'll be sure to post the outcome! Hopefully will include a nice shiny new rig:D
You'll be right about that one bridge, that's why I think having a long offroad tow bar length is a good backup.

Calcs for performance are vague - we just thought 450hp seemed about right... Haven't even given gearing a thought The hino it's replacing sees top about 30% of its driving time. Do want rear springs though. Economy, well that hasn't been a factor in decision making. Running costs - as the company likes to keep equipment for a very long time (most vehicles here they've had since new and several are 30 or more years old) and that's why I'm thinking simple, least electronics as possible and good parts availability in the future. That's why I'm pushing a yank tank due to good parts commonality and not much proprietary electronics. And the fact I hate matt plastic on trucks - what is the euro obsession with it? What's wrong with a little chrome? (This is coming from a guy who moved from the UK 3 years ago)

More grey cell activity Wedge, 7200 is too long as you say. T409 would need to be about 6700 or Metroliner 6950. Cab position and overhang determine wheelbase, with a check on steer axle loading. The Metroliner has 4350 on the steer as cab/chassis fueled up, say 4.5 tonnes with driver and a bit of gear. Bullbar would add to that. Guessing the T409 would be similar. Longest standard Metroliner is 6300, but longer made to special order.
T409 diagram shows (175 + 1235) = 1410 bullbar to steer axle centre. Axle centre to tray front (1705 + 130) = 1835
Maximum overhang 3700. Try 3650. Tray length 8500 puts 4850 of tray forward of drive group centre. ( 8500 - 3650 ) Minimum wheelbase is then (4850 + 1835) = 6685. Try 6700. Overall length is then ( 3650 + 6700 + 1410 ) = 11760 Formula on last post gives steer axle load. D = 600 L = 15 tonnes W = 6700 F = D X L / W = 1.35 tonnes.
Hayseed posted a link for the Metroliner, the diagram shows bumper to steer axle centre 1008, add a bullbar say 1200. Axle centre to tray front ( 2670 + 400 - 1008 ) say 2060. Try overhang at 3610. Puts ( 8500 - 3610 ) = 4890 of tray forward of drive group centre. Wheelbase is then ( 4890 + 2060 ) = 6950. Overall is ( 3610 + 6950 + 1200 ) = 11760.
Steer axle load from D = 640, L = 15 tonnes & W = 6950. F = 640 X 15 / 6950 = 1.38 tonnes.
Reducing overhang and lengthening wheelbase adds to steer axle load. Have adjusted figures to give similar results for each brand. Good to reduce overhang as much as possible to help prevent chassis and drawbar clashing. Dealers can make these calculations for you but best to be prepared as you are doing. Hope this helps. Cheers, Paul.

Wedge,
Sorry about the delay but work got in the way again.
I put the tape over the old T Line today and came up with this.
Gap between bodies (max height 4.3m) =1130mm. Could be closed up another 100mm safely.
Length of drawbar(start of body to centre of eye)=1830mm
Set back of hitch from rear of truck body=700mm
Height of hitch from ground level=550mm.
We have been using VBG (load bearing ringfeeder type) hitches for the past 20 odd years. Would recommend these over the Bartlett Ball hitch everyday of the week. We lost 4 trailers from Bartlett Balls breaking and since the change have never had a problem. These all were pre-safety chain days.
Being a pig trailer you will need a load bearing hitch so you cannot use a Ringfeeder (these are not load bearing, only designed to pull).
My T line was stretched from new(one owner) in 1988 and have never had a problem. Back then if you wanted something with decent power/running gear you stretched a prime mover.
If you need anything else let me know. Only too pleased to help.

David

Wen all else fails






try thiz mob for hitches

Clikity ..... ClikClikClik

cya

T and Paul - that's a huge help thanks. Didn't get a chance to go over figures today as have been driving all over the place looking at rakes. Tomorrow gotta set a bore up, hopefully thurs I'm back on it. Although have been told rake is top priority right now which is a shame as it's put a truck decision/purchase back a couple of weeks

Paul your drawbar is a good conformation of normal clearances. I'm very confident we can get what we want with a bonnet. So yours is a bit longer than the powerstar shown, and a fair way under the tray. Do you ever have issues with the tray hitting the drawbar through dips? Where's your spare? Another good reason for having the hitch right at the diff would be ground clearance too I guess. Nice one on the hitches I was assuming bartlett ball but might rethink that now!

Paul that's a good comparison thanks. Not sure about a Metroliner but very into the T409, although not sure if they'll want to go the extra $10k for the SAR. Nice axle spacing and cooling I know (obviously looks fantastic too) but any other reason? That aside, looking at Macks at agquip didn't do it for us, love the old ones but not the news. Might number crunch a WS 4800FXB though. Not sure about the link between mack and WS - how does it follow if Mack has a certain WB WS will too? Max WB listed for the 4800FXB is 6.4m but will see what that puts the overhang at.

I'll see what the body builder says about hitches but I'll check those out swishy

OK here be my set up. Truck and pig with two trays about 24 and half feet long, gap in the centre is around 900 mm at the crates (less at the bumpers) tow hitch is about 750 mm in from the bumper, 2900 mm front of bar to front of crate. Total length = 19m. The truck and trailer are closed for loading in the pic.

I go through some very average gateways at times and the crates do have a few battle scars from touching at the top but no damage besides some missing paint, one thing though my draw bar pivots and some times a gate you can drive in and out of you can't always reverse into without the crates touching. : Debo

Gr8 pic Debbo
Keep m Cummin

? Iz th@ a clip on crate ?

cya

Gr8 pic Debbo
Keep m Cummin

? Iz th@ a clip on crate ?

cya

Thanks Swishy re the clip on crate? no the truck crate was built as a one piece and the trailer crate I welded on a few years ago when I rebuilt it. Why? to stop the effluent leaking between the crate and tray and the rust that then starts and also its a great excuse to not cart hay!

pretty good looking set up you got there Debbo, I assume 24.5' of cattle deck warrants a tri axle then? So if you have 49' of deck, and 900mm in between that leaves you 3165mm for the cab and between cab and tray. Seems a lot for a cab over, or is that a deceptively large sleeper? It's just going on the early stage of this thread I would have thought you could squeeze more than 49' of tray space into 19m with a cab over. Do you have more than one towing length? How is it on rough roads - very choppy? Tray hitting the towbar through creek beds?

On a different matter - the GVM and front axle weight is now concerning me. Firstly the volvo FMX we've been quoted on tares at over 10t, so we've a 13t payload limit. And it tares at 5.1 on the front axle, so with an overhand of 3.6m anything over 12.2t centered on the tray (going on Paul's equation) is overweight on the front. I figure a 28' tray full of cattle (going on 600kg per 12 sqft) is 11.5t, add a tray and crate and I'd say we're comfortably over that 12.2, maybe even over 13t... So that's a no goer for sure. Let alone hay - 24 bales at 600kg is what we'd like to cart so 14.4t!

So we could go a shorter tray and longer trailer. But really a bonneted truck with a lighter front tare and maybe even lower overall tare would be better... Anyone know what say a T409 with a ~6.7m WB or another similar truck like a 4800FXC 6.4m WB (I know couldn't get a 28' tray on but might be looking shorter now anyway) tares at?