Master Logger,
I know exactly what you trying to achieve. Let me repeat for you.
Your truck empty weight about 15,000 lb
Your trailer is about 10,000 lb
And you timber goes up to 50,000 lb
So you have about 75,000 lb on muddy roads. So your toys are sinking.
Let see some numbers:
truck weight + 1/2 trailer weight + 1/2 load = 45,000 lb sitting on 6 wheels 14R20.
The ground pressure is 25.79 PSI.
Just compering to 6 wheeler civilian truck loaded 33,000 lb. It has 33.53 PSI.
So it is not bad.
however if you comparing to 200 lb person standing on one foot - about 10 PSI.
If you will put dual 14R20 on back you truck will create 15.47 PSI. Wow it is grate.
Just to play around I plugged into my calculator:
Configuration now:
Front - 14R20
Rear 2 axles - single 14R20
Pressure = 25.79 PSI
dual 14s configuration:
Front - 14R20
Rear 2 axles - dual 14R20
Ground pressure = 15.47 PSI
What if you put single 16R20 instead 14R20 -
front - single 16R20
rear 2 axles - singles 16R20
Truck's pressure - 19.24
apparently it better when single 14s but not as good as dual 14s.
I got some other configuration for you:
front - 16R20
rear 2 axles - 24R21
pressure = 15.19 PSI
whey (16s and 24s) very close by diameter.
Lets see if you can add one more axle on back:
Front - 14R20
Rear 3 axles - single 14R20
Pressure = 19.34 PSI
Front - 14R20
Rear 3 axles - dual 14R20
Pressure = 11.05 PSI
Front - 16R20
Rear 3 axles - single 16R20
Pressure = 14.43 PSI
this is some interesting ideas ...
I know exactly what you trying to achieve. Let me repeat for you.
Your truck empty weight about 15,000 lb
Your trailer is about 10,000 lb
And you timber goes up to 50,000 lb
So you have about 75,000 lb on muddy roads. So your toys are sinking.
Let see some numbers:
truck weight + 1/2 trailer weight + 1/2 load = 45,000 lb sitting on 6 wheels 14R20.
The ground pressure is 25.79 PSI.
Just compering to 6 wheeler civilian truck loaded 33,000 lb. It has 33.53 PSI.
So it is not bad.
however if you comparing to 200 lb person standing on one foot - about 10 PSI.
If you will put dual 14R20 on back you truck will create 15.47 PSI. Wow it is grate.
Just to play around I plugged into my calculator:
Configuration now:
Front - 14R20
Rear 2 axles - single 14R20
Pressure = 25.79 PSI
dual 14s configuration:
Front - 14R20
Rear 2 axles - dual 14R20
Ground pressure = 15.47 PSI
What if you put single 16R20 instead 14R20 -
front - single 16R20
rear 2 axles - singles 16R20
Truck's pressure - 19.24
apparently it better when single 14s but not as good as dual 14s.
I got some other configuration for you:
front - 16R20
rear 2 axles - 24R21
pressure = 15.19 PSI
whey (16s and 24s) very close by diameter.
Lets see if you can add one more axle on back:
Front - 14R20
Rear 3 axles - single 14R20
Pressure = 19.34 PSI
Front - 14R20
Rear 3 axles - dual 14R20
Pressure = 11.05 PSI
Front - 16R20
Rear 3 axles - single 16R20
Pressure = 14.43 PSI
this is some interesting ideas ...