Spread Trailers

Howdy,

I reckon a topic on spread bogies would be good.
Im familiar with the McGrath suspension setup and seen a pic of a hydraulic suspension but what other types were used ?
Ive been wondering for awhile about when did spread bogie trailers start to become popular and when did they get phased out ?
Was it the tri axle that killed the spread bogie's off or the law ?
Any pictures would be good

Basil

Bazil
Gudday M8

the very little eye kno on the subject sez:
from time way back a natural progression
Single axle trailer
Tandem axle trailer
Tandem spread axle trailer
Tri axle trailer
the spread axle of a 10 foot spread = 15ton over group
a tandem 13.3 ton
so there twaz advantages with a spread
this is B 4 Tri axle trailers were alowd for general cargo
most spreads needed sweepers to help prevent flat tyres
as the front axle drove over a nail n stood m up they would puncture the 2nd axle tyre so the idea of a set of sweepers twaz to nok the nails down again (they did work)
Also heard when a spread trailer was loaded n do n sum tight manouver n the tyre scrub would pelt stones out from under the wheels

ButWaddaEyeKno
LOL

E&OE
Cya
[ch9787]

Thanks Swishy,

I know there has been a previous brief topic on the forum about spread trailers but id like to learn more about them. Im sure others on the forum would be interested also.
Things like where did the 1" come from on the axle spacings ie 9'1"
Pictures and info on the different suspension systems used. Im familair with the McGrath setup but would like to learn more about the hydraulic type and Ive heard about a Freighter inboard walking beam but never seen one.
Any pictures from the times they were used would be great also.

Basil

Here's a few photos from the albums.



They're Haulmark 9'1" spreads and carried 16t on the spread, gave a gross of 28t which was an economical unit.
Haulmark originally used a longer version of their close bogey's equalizing beam running from the rear of the front spring to the front of the rear spring.
Later they went to a bell crank setup similar to the Leyland's bogie.
Both had the same articulation.
McGrath also used the long rocker beam but Freighter went off the rails a bit and used their "walking beam" design which went from the rear of the front spring to the rear of the back spring. Of course this meant the equalizing beam has to be mounted inside the main chassis beams which induces an eccentric load on the walking beam's centre bearing. It was a pretty horrible idea.
Here's a photo of my strap type Freighter close bogie, you can see the end of the equalizing beam and its eccentric loading.
Hydraulic equalizing was popular on sliding (adjustable) bogies but they were all left in the dust once airbags became popular.


Swishy is correct about the nail sweeps and even with the sweeps we still had punctures.
They turned fine, minimal scrub and on the road they ran nice and true.
The small Commers had some trouble pulling them around a tight corner but they were only 7t trucks.
Without a doubt Haulmarks were the best finished trailers for the price.

The 1" bit came from the Main Roads bridge deck beam spacing, which in our area was 8'0".
So if your spread was 8'1" you only ever had one axle on the deck beams and so you were permitted 15t?? on the spread.
We went to the 9'1" spread as D.M.R. then gave us the loading allowance of 16t.

g'day GM Diesel and all .. have out in the back yard a 1972 37 foot freighter TAA 27 bogie pantech, three way adjustable spread and hydraulic rocker suspension...has the meat rails and still has the department of agriculture code on the front corners...

we reckon the pan would look good behind the TNT kenny but not sure if they used the three way spread dry pans in their fleets...any clues anyone ?

it would be pretty heavy, with the carrier transicold unit under the floor, still in place (complete with four cylinder perkins running things) but once again...a complete time capsule...

i'll get jason to upload some pics of the suspension and whatever else from his 'phone....cheers

ps jeffo...nice pics

Check these pics out.

At Allora show a few years back


Freighter hydraulic cutoff at Elsmore

SUS info





me thinks each State had there own version of wots right for weights etc
Cya
[ch9787]

Many, many haircuts ago, BP used a spread axle to supply fuel to servo's. However, at that time, the majority of garages were a lot smaller. Subsequently the tyre blowout ratio on the spreads was horrendous. The engineers alleviated this by setting up the forward axle as a steer. Worked rather well!
Take it easy,
Leon.