Winching demo at Land Rover Max, Newark 2009

[pimpUK1]

Its not pulling 27t though!

Its only a estimated pull of 7t. Would probably be nearer 3t in reality as the ground is more like hardstanding. Try lifting it up a vertical cliff, then it will be pulling 27t! The Fodens front winch is only a 10t winch.

[widget3]

Thanks for that guess - at no point did I say it was pulling 27 t. I said it was pulling a 27t truck. Try reading a bit further down the comments for Stonefisk's calculations from the REME Recovery manual which is 3.75 tonnes on short grass.

[pimpUK1]

I am a Reme reccy mech so I must be wrong then. Stonefish must know more than me and all other trained reccy mechs then.

Always round everything up when making a EP. RR is 4t, GR 1t, DR 0t, SF 2t EP 7t. Squaddie maths, Keep it simple.

A EP is always a guess which is why the E stands for .............Estimated and why you have a safety factor within the EP!

You keep to your advice from the net and surplus REME manuals from Ebay then.

[landyrover4x4]

wow there i am in the hoodie on the right, next to the barrier and flag thing. good show to be fair.

[BlesamaSoul]

most warns fitted as standard should shift that truck no problems?

[widget3]

Absolutely - but the limitations are the battery capacity and duty cycle on the winch motor.  Hydraulic has neither of these issues.

[BlesamaSoul]

spot on and good point, I was just thinking grunt and not the long haul! If you were kitting out a Discovery 4 could you add a hydrolic winch and any suggestions?

[widget3]

How about a Milemarker H12 and an ARB winch bumper?

[BlesamaSoul]

ah ARB yes i was trying to remember one I had seen before thanks for that!

[widget3]

8274 would need double line?

[widget3]

Blimey - that's all very technical - but makes good sense. Thanks.

[stonefisk]

Previous calc was for short firm grass, increases for long. GroundFactor = 7 (Long Grass) WeightofVehicle = 27 tonne RollingResistance = WOV/GF RR = 27/7 = 3.86TONNE GroundResistance = (WOV X Deg of Slope)/60 GR = (27 x 0) /60 = 0.45 TONNE DamageResistance = 0 TONNE 3.86 + 0.45 + 0 = 4.31 TONNE Safety Factor = 4.31/4 = 1.0775 Estimated total pull required = 4.31 + 1.0775 = 5.3875 tonne = 11,877lbs

[stonefisk]

So it's approx 27 tonne rolling load on 6 wheels with the friction coefficient factor of wet but firm short grass on a flat surface...... so that really only equates to a winch load of about 8300 lbs in worst case when calculated using the formula depicted in the REME recovery manual. Most popular modern winchs found stuck on the front of landrovers could do that with a straight line pull.