Lorry, 4-ton, APF and Lorry, 4-ton, ZPI - Details needed

[Joe C]

I'm looking help digging out proper identification, more information, details and/or pictures of "Lorries, 4-ton, APF" and "Lorries, 4-ton, ZPI". These vehicles appear in the list of current vehicles in Canadian Army Overseas Routine Order 2872, 11 December 1942 but I haven't been able to dig up details on them.

As background, APF and ZPI were radar systems in the GL III(c) gunlaying radar used for air defence. The Lorries in question were the movers for the trailers. I have photos of what I believe are the two vehicles [1][2] taken from a series taken 26 Jan 1943 of 1 Radiolocation Unit [3] and so I think it's a good assumption they are of the named vehicles.

So, specifically, my questions would be:
- What make/model of Lorry are they?
- To me they look like "stock" lorries, what customizations made them 'unique' enough to give a name to them? As they had two names, I'd infer they had two different configurations/designs.
- Does anyone have other period photos of these lorries to share?

Anything would be welcome!

[1] http://www.rcsigs.ca/index.php/Lorry_4-ton_ZPI
[2] http://www.rcsigs.ca/index.php/Lorry_4-ton_APF
[3] http://www.rcsigs.ca/index.php/Radio..._Unit_GL_III(c)

[Tony Smith]

The trucks that towed the APF and ZPI trailers were FWD HAR-01 trucks.

A couple of threads on the matter:

http://www.mapleleafup.net/forums/showthread.php?t=4881

http://www.mapleleafup.net/forums/showthread.php?t=3459

[Joe C]

Thanks Tony! That takes care of the vehicle make/model. I'd still love to see period load lists or designs to show if there were any special configurations for the rear portion.

Lots of Australia photos but much less ones of Canadian kit. I'll have to look into the usage restrictions for AWM images...

[Lynn Eades]

Did those trailers have electric brakes, that required the trucks to be fitted out for the trailers?
I was an apprentice mechanic in the early 70s. My unit was an LAD and as such we looked after an Artillery unit that used 5.5 guns. These guns had electric brakes. The gun tractors were Australian built Mk5 International 6x6s.
They were fitted with a large hand operated rheostat to activate the gun brakes. They were not connected at all to the foot brakes of the trucks. Anyhow I digress. You radar trailers would have been quite heavy leading me to think about this possibility.

[Richard Farrant]

Hi Joe,
You are asking about the FWD trucks that were part of the Canadian radar convoy, there is a restored HAR-01 for sale in England currently, see here:
http://www.milweb.net/classifieds/vi...ad=82164&cat=4

I am involved with the Corowa Swim-In military vehicle event in Australia and was instigator in obtaining a ZPI trailer to use as the event's office. Since then two other ZPI trailers came on the market. These two have been bought by two other military vehicle groups, one in Sydney, the other in South Australia, both to be used for similar purposes. It is known that Truck Engineering had the contract to build the ZPI trailers, but one of these two had a build plate of Massey-Harris Ltd. Through my research, I found out that Truck Engineering had rented part of one the Massey-Harris factories, and it may be likely that they were helping keep the production up. Electric brakes were also mentioned, yes they were fitted with Warner electric brakes as far as I know.

Mention was also made about generators, one of the two FWD's had a Cummins powered generator in the body.

regards, Richard

[Ilian Filipov]

Hi Joe,
In his excellent study on FWD HAR trucks in "Wheels & Tracks" magazine No.5 Bart Vanderveen wrote this:


http://postimg.org/image/ilqzow771/


HTH
Cheers!

[Joe C]

Fantastic info, thanks!