30-cwt vs. 3-ton Difference

[Hanno Spoelstra]

Originally Posted by Tony Wheeler

It's worth noting that design factors such as auxiliary springs, diff ratios, steering boxes, big balls v. small balls etc. do not define load rating - they simply reflect the way a particular manufacturer designs their range of 8, 15, 30, or 60 cwt. vehicles, as defined above. Which means the whole question of load rating is far simpler than it appears - once you figure out the rules!

Tony,

I'm afraid this is not entirely correct. The British War Office classification was a load classification, regardless of the technical configuration of the vehicles supplied by manufacturers.

Load carrier trucks have a load rating, tractors do not - see the thread Is the FAT a 60cwt or 15cwt truck?.

To be able to carry the load and move it at convoy speed across country, manufacturers configured their trucks from existing components. As stated above, I sorted out the difference for Chevs recently, see Chev CMP chassis views. One can see clearly that the heavier the load rating, the heavier the truck's components are - so "design factors such as auxiliary springs, diff ratios, steering boxes, big balls v. small balls etc." in fact do define load rating!

Originally Posted by Hanno Spoelstra

C30:

• Front axle with 5” steering ends
• Brakes, front drum: 14” diameter, 2” width lining
• Brakes, rear drum: 15” diameter, 3.5” width lining
• Wheel size: 16” rims
• Differential gear ratio: 7.16 to 1
• Rear spring leaves: 12

C60S:

• Front axle with 6” steering ends
• Brakes, front drum: 15” diameter, 3.5” width lining
• Brakes, rear drum: 15” diameter, 3.5” width lining
• Booster actuated brakes
• Wheel size: 20” rims
• Differential gear ratio: 7.16 to 1
• Number of rear spring leaves: 12 + 6 Aux.

Originally Posted by Tony Wheeler

On the question of LWB with 16" wheels, eg. F602L pictured above, I suspect these are rated for on-road use only, just like MCP vehicles. As such it would equate with the Dodge T110L5 (160" wheelbase, 16" wheels, 2-spd diff) which is rated 3-ton.

The F602L has a 3-ton load rating, as has the Dodge, the fact that they had 16" wheels has noting to do with their load rating. They were fitted with 10.50-16 tyres to bear the load.

As per Vanderveen: "Truck, 3-ton, 4x2, GS (Ford F602L) V-8-cyl., 95 bhp, 4F1R, wb 158-1/4 in, 243x90x118(78) in., 7280 lb. Latest type, using many components of F60L. Tubular front axle, two-speed rear axle. Also with four-stretcher ambulance body and 134-1/4 in. wb GS with open cab."

HTH,
Hanno

[Tony Wheeler]

Originally Posted by Hanno Spoelstra

Load carrier trucks have a load rating, tractors do not - see the thread Is the FAT a 60cwt or 15cwt truck?.

Hanno, Tractors do indeed have a load rating, despite not being load carriers. I conclude therefore it refers to towed load, not carried load (as mentioned in my post above). Pretty obvious when you think about it but we overlooked it in the thread you mention.

img008.jpg img009.jpg img007.jpg

[Tony Wheeler]

Originally Posted by Hanno Spoelstra

One can see clearly that the heavier the load rating, the heavier the truck's components are - so "design factors such as auxiliary springs, diff ratios, steering boxes, big balls v. small balls etc." in fact do define load rating!

I suspect we're getting into semantics here Hanno! To put it another way - Load Rating determines components, not the other way around. Hence F60L with small balls is still F60L.