European trucks

@Pablo-UA and @daf105paccar I think are pretty familiar with Euro trucks.

 

They are as close as possible.
That comes from the lenght laws.A semi is limited to 54 feet 1 inch with a max trailer lenght off 44 feet 7 inches.
The longest can you can haul is a 45 footer.
But getting that close also means better MPG.

 

As Daf105 paccar already write,

-our legal limits are 16500mm (54 feet 1 39⁄64 inch) for tractor+semitrailer overall length( bumper to bumper)
-Max king pin to rear of trailer length is 12000mm ( 39 feet 4 7⁄16 inches)
-Front bumper to king pin remains 4500mm (14 feet 9 11⁄64 inches) (but there is no law about it it is just remaining max distance, you can have this distance longer but this means shorter distance of king pin to rear of trailer)
-Max trailer swing radius is 2040mm (6 feet 85⁄16 inches) -this is distance between king pin and front corners or any other point on front of trailer, this makes use of normal 45ft containers illegal in EU, you need to have 45ft euro container with different corners....


-2040mm law makes all our trailers to use cut off corners....corners are not farthest front of trailer ( trailer is 13589mm long from corners to rear end) , there is front wall , brackets for air and electrics, refrigerator on reffer trailers , hydraulic cylinder on tipper or tipper bulk silo tankers etc....

Theoretically trailer can be 14040mm outside but only in middle....
Longest cab currently on market is 2300mm long (7 feet 6 35⁄64 inches) , when you do math 4500mm-2300mm=2200mm
2200mm-2040mm=160mm

exact 160mm is distance remain , it is used when truck and trailer are not on flat but this distance allow movement of truck....

when truck is straight, on flat road, with normal curtainsider trailer you have about 520mm between cab and front wall..... side spoilers on tractors can be 350mm behind cab....so there is no more than 250mm of distance between rear of spoilers to front corners

 

and in case if you are wondering there is even more math and engineering to make straight trucks with full trailers legal..... in many cases they cant do full movement or otherwise you might hit your own trailer.....

 

I have spend several years doing calculation what can be possible and what not.....

It is not problem for trucks with central axle trailer,
-law says total max length 18750mm ,
-minimum distance between truck and trailer 750mm
-max sum of body lengths of truck truck and trailer 15650mm
= remaining length is 2350mm , longest cabs are 2300mm so you have comfortable 50mm between truck and truck body.....this makes comfortable 38€ pallet spaces, no problem....

problem is if someone wants 39€ pal....than you need to steal some space and do careful calculation how to fit everything inside....it usually looks like...

you need to take brand with shorter cab, Volvo is currently shortest cab truck....fit thin front walls and doors, but keep in mind you still need to comply with DIN EN 12642 about load safety certificate...reinforcement beams in front of truck body is your largest problem, you need to find out solution how to replace them in front corners, but still comply with XL cert.... you need to reduce distance between truck body and trailer....this might be dangerous , and driver must be aware what does he drive..... you need to move trailer hook further-deeper inside of truck....this reduce turning radius.....need very precise calculation about trailer axle positioning , make it too short trailer dont behave good, make it too long , turning radius don't fit into....steering tag axle on truck makes things much better.....

 

Trucks with full trailers are more problematic for calulations.....if you fit normal bodies of 6.1m+8.2m or 7.1m+7.1m or 7.3m+7.3m this is not problem anyone can do that.....

But if customer wants longer bodies , you need to reduce distance between truck and trailer, you can do that only by placing hook deeper inside truck and front axle on trailer.....if hook is on normal position and not under truck that makes much more complicated to create subframe as there is no truck frame in last 1m or similar....also you have to place towing beam more deep inside of chassis not to its end but in same hand keep in mind when calculating to place it not too much inside otherwise drawbar might hit chassis rail....

when you set front trailer axle deep inside trailer, you must keep in mind this would reduce wheelbase or otherwise you might have problems with front axle weight..... make it too short and trailer become unstable.....

more you move trailer hook and trailers front axle deep inside , drawbar becomes longer,every cm longer drawbar is you get more and more problems , truck pull trailer with very strange angle when cornering ......

you can lose whole day trying to find perfect( that don't exist) setup how deep you can put hook, and how deep trailer front axle , and which corners cuts to get less chances truck will hit trailer when cornering......



see lines of steering , they cut each other by 100mm , this truck should be about 250mm longer to be safe there would be not problems.....

 

if this sounds too much for you.....than take a look at this....

1980s were crazy , everything was about volume, and they did not looked way to achieve goal....

back than total length was 18000mm and they used to fit 40€ pallet into these trucks...... pallet is 800x1200mm.....

how is that possible...


Normal setup was like this on photo, mostly Man unterflur, equipped with 2x swap bodies

math goes like this:
-18000mm total length
-8050mm outside dimm of swap body
-560mm between truck and trailer
-1330mm cab
-10mm between cab and first swap body

to fit 20€ pal into 8050mm body , you clearly need to use thin front walls and rear doors....they use sheet metal instead of aluminium panels to save space , no reinforcement beams in front of body.... rear of truck often had just trapoulin

Since it is not possible to fit engine under 1330mm cab, engine was between axles, it was horizontal lying engine , such trucks were unsafe, short cab means you get pinched in crash, no engine to protect you , and load might get inside since front wall was too thin.....)

Volvo used bus chassis to save space, Daf used to move cab forward truck had side mounted radiator.....other brands never get full 1330mm cab, Mercedes made 80mm shorter cab , they specially made V6 engine to fit it under shorter cab but never get full volume....Scania's politics did not allow such things, altrough Scania importer in NL tried to make it itself, they take water intercooler to save 5cm space on front, they replace front axle and cut cab on rear but it was not even close to 1330mm i think it was cca 1500mm



Europe finally ban that and make laws that limit max allowed sum of body lengths....., than in 7/1996 they extend total length to 18750mm....

 

if you think that all this is too crazy.....

no it is just child play comparing to telescopic drawbars.....basic idea was same, to get more volume,

they were extending when truck is cornering and keep trailer close when going straight....

each manufacturer get its own idea, first ones were from late 1970s , based on mechanic principles only....

some manufacturers used 2 drawbars, and 2 hooks one was to rotate trailers axle , other to pull trailer , or one to control valves and other to pull trailer,

some manufacturers had elliptical axle guide and unlocked drawbar.....
Latter hydraulic system appeared on market.....in its best version it could reduce truck-trailer distance to only 350mm !!!!