mammoth

Thanks for that very useful information. It is amazing that chassis design only 4 numbers apart could be so different, definitely a trap for the unwary. If 860 is the outside diameter and allowing for band and tyre thickness X 2 the rim size might even be less? Also in this very early era I am guessing that a shakeout to standard sizes had yet to happen. My plan is to have the (wooden wheel) wheel and tyre bands custom made in which case there will not be a need to build to what became a standard size. 853492008_DennisTheadengine (1).pdf This is the correct (?) version but not such a good image. Stay safe Ben

I believe they would be 1920's Albion 24 series. It is on FB and seller wants $1,000, but not communicating.

These are large tiff files of 3033, now fleet No 24, at Manly station (from 1921) so download and you can zoom in for super detail. 9000-15678.tif

As far as getting new wooden wheels go Ben advises that the wheels were probably outsourced and hence there are no Dennis drawings. However, he has found a drawing of a smaller wheel which is helpful in the general scheme of things as it matches the remains of mine construction wise. What I need now is some wheel measurements from LE9588 (diameters and width of bands and tyres) which was built the same year and only a few chassis numbers apart although I understand it is currently laid up at Woburn (?) and not on public display. 9000-15682 (1).tif

Some updates following research enquiry to Museum of Fire, Penrith. NSW Fire Brigades record that 3035 (sic) and 3055 were delivered together on 30th Jan 1912 and were allocated fleet numbers 56 and 57 without any notation of which fleet No was allocated to which chassis. No. 56 went to headquarters and was disposed of in 1931 by way of auction while 57 went to Newcastle where it remained until withdrawn in 1929. No record of disposal. The obviously poor record keeping procedures of the time did not identify the clerical error of using the wrong chassis No. Chassis 3055 is recorded as having engine 4729 and body 3262. I believe this is what the original motor looked like

The wheel is from a 3/3 ton Leyland RAF type. PM sent.

The strange radiator protector on the McGhie's K type was not a one off as seen on the Whitbread's K type subsidy model.

Just why a model specially designed for the British subsidy scheme and more expensive (750 pounds vs 685 for the J) should be sent to Australia is a mystery. Chassis 1198 built 10/04/1913 was sent to McGhie Motors in Brisbane. Four other K types were sent to Australasia one in January and three in June 1914.

K type front.pdfFurther research has found what may be the only surviving image of Thornycroft's double reduction rear axle. The images from front and rear show the banjo style casting which cradles the gear casing. The torque tube can be seen attached to the top of the casing. The raised "set frame members" can be seen either side of the silencer. K type diff.pdf The front of both the J and K types wore a badge on the radiator with the legend "Thornycroft motor'.

Correction as I haven't worked out how to edit. VCV magazine 44 has an article by Bill on Thornycroft engines and it is No 52 which has the article on J & K types.

J K photos-001.pdfThe magazine article written by Bill Dawe back in 1994 now sheds more light on this model. Thanks to Bill's research back then I can now offer the below information. The K model was designed specifically to meet the design wishes of the Mechanical Transport Committee of the War office. In addition to a double reduction drive axle a torque tube arrangement was required to control axle location, rather than relying on the springs, and so the rear axle and shackles front and rear which it's sister J model did not have. The first K was chassis 1177 sold with a subsidy to Pickfords on 24/10/12 and was shown at the 1913 Olympia Show. A total of just 60 K types were built with 26 going to private hands.and the remainder to the War Office. Towards the end of production the M4 motor was fitted randomly and then as standard and the last one was chassis 2206. The transition to the WD version of the J model followed the War office recognition in 1914 of the failure of the subsidy program due to the onerous and expensive specification. ( Commercial Motor was scathing of the "subsidy muddle" and Johm E Thornycroft complained publicly) The rear axle specification was dropped and so Thornycroft immediately submitted a K model fitted with the J worm drive for approval. and from this point the K model ceased production. Thornycroft were a major provider to the navy and so at declaration of war big orders came in. The firm gave priority of steel castings to the naval orders (all manufacturers at the time had trouble sourcing steel castings) and so the pressed steel wheels came into being, concurrently with a re-design of the of the early J to become the WD. J model. The chassis now had conventional rear cross members, front axle shackles at the rear of the springs, steering tie rod to behind the axle, and petrol tank moved from under the seat to the fire wall. A new radiator which was lower and fitted between the chassis rails was introduced, although old stock high radiators continued to be fitted in early batches. J K photos-001.pdf

Sometimes you should look at what is right under your nose and indeed on Dave Rossington's prompt I looked on my shelf to find Vintage Commercial Vehicle magazine number 52 had an article "Thornycroft J & K Types" written by Bill Dawe who still resides in Ballarat, Victoria. The information more relevant to the Subsidy K type and the transition to the WD J model I will post in that topic. In brief, the 1912 'heavy range' comprised of the 2 ton C and 21/2 ton D model both with worm drive and L4 motor. The mysterious 4 ton H model was withdrawn before any were sold and replaced by the 33/4 ton J and 41/2 ton K aimed to meet War Office subsidy specifications. The first J was chassis 1178 sold to J Wrigley & Sons in August 1912 and on display at the 1913 Olympia Show. 63 'J' were sold into private hands and the remainder to the War Office. From Chassis 1358 the M4 motor was appearing on some J chassis and the last one to have an L4 motor was 1382 dispatched on 16/1/14. The J and K chassis numbers were muddled up so takes some deciphering to tease it apart which Doug has been doing and has worked out that mine is the 41st J. J K photos-001.pdf

The photo above is of my early J type which was equipped with a new design worm drive rear axle. The K type was reported as a new design in Commercial Motor in September 1912 with rating for gross load of four tons whereas the J was rated at 3 1/2 tons. The K had larger wheels back and front and described as more robust but no detail is given of what the differences actually were. It carried the prescribed brush bar in front of the radiator and tow hooks back and front. The K type was inevitably significantly more expensive, more of which later.

If I may indulge the moderators I have created this topic in the hope that more information concerning the Thornycroft K type, otherwise known as the WD subsidy truck, built between 1912 and 1914. This model was very similar to the early 'J' type of which only two survivors are known - see Aussie Thornycroft topic - which in turn is naturally confused with the subsequent and more familiar war time and later 'J' type with disc wheels. I invite all contributions and corrections. The only manufacturer's illustration that I have come across is here; http://archive.commercialmotor.com/page/29th-january-1914/12 where is was displayed at the Manchester Show. During the first decade of the twentieth century Thornycroft were keen to put their products in a good light with the War Office/War Department. It wasn't just steam and internal combustion vehicles that they produced but naval vessels as well. Accordingly the company made a significant effort to meet compliance with WD design requirements. The story of the various trials is much greater than can be covered here but were reported on by Commercial Motor magazine. The subsidy scheme came into being with a prescribed design criteria determined in 1912. The WD favoured a double reduction differential having been impressed with the Leyland rear axle (the same arrangement was used by Volvo and others into the 1970's) in previous trials, although chain drive was still accepted, albeit at a lower subsidy. Thornycroft, not wanting to take a competitor's design, designed a completely double reduction arrangement which was granted a patent in Dec 1913. http://archive.commercialmotor.com/article/14th-january-1915/20/patents-completed. The design was reported in Commercial Motor for the Olympia Show issue in June 1913...."run the propeller shaft horizontally to the rear, from a bearing carried in a special cross member to the top of the back axle housing, this shaft then gearing vertically below it by spur gears, which constitute the first reduction, the final reduction being by bevel in the usual way. " The K type was the first to be granted a subsidy certificate and participated in the WD trials in 1913 and performed very well over the total of 1500 miles. This design, would have made the diff housing very tall and I speculate that the unique raised cross members shared with the J were to accommodate this.

I have come to the conclusion that the identity of the early J type is very much tied up with the subsidy K type and with so little to go on I will start a new topic on the K type and invite comments, corrections or even shoot me down in flames when I have run away with speculation! The Rod Dux book has been helpful while the Commercial Motor archive has helped to provide a general picture and a few faint images. My J was sent to the Brisbane dealer W,F, Turk & Co from where the trail goes cold. I have traced a previous owner who had it for about 30 years having purchased it from a deceased tractor collector who also had it for some time. The previously mentioned purchase of trucks by the Australian army occurred in Adelaide, Melbourne and Sydney, so being in Queensland mine missed the call up. I am speculating that the chassis for both J and K types was identical and therefore features such as the raised rear cross members were common to both when they were only actually needed on one. (see the K type topic). The K type chassis differed by having the rear springs shackled front and rear. In price lists the early J type was variously described as ; 3 ton; 75 cwt, charabancs chassis, the latter possibly having the M4 engine and was sold alongside the K type.

Seems they were sold in Britain prior to war http://archive.commercialmotor.com/page/29th-january-1914/14

Leyland recommended not to bump start their worm drive models, however my mate starts his 3 tonner that way all the time. In Australia because of the long distances, little traffic etc it was usual to use 'angel gear' on down hill sections thus increasing speed from the usual maximum of 30mph. Not a safe practice but they did it. With heavy worm drive diffs over-speeding in this way means that eventually the worm can't keep up and the top literally blows off. As said, effect of engine braking is down to the ratio.

Amazing find, well done. What is the big set of wheels?

On the other hand it could be a farm special made from a later model with a model T axle or chassis stuck under it.

I just remembered I have a copy of 'The Book of the Thornycroft" by "Auriga' sitting patiently on the shelf since 2006. As it covers the WD J model with M4 engine it is a useful reference to identify differences of the 2013 model variant. It also includes the faults which required re-design between 1914 and 1917. On the subject of engine mounts there was clearly trouble related to chassis flex which was addressed with the 3 point engine mount just described. However, this modification caused misalignment between crankshaft and gear input shaft causing various calamities including fractured crankshaft. The subsequent, and successful, modification was to mount the engine rigidly on the sub-frame which was then fixed at a central point only at the front. (similar to American practice at the time.)

Re engine mounts:- 4" square Australian hardwood would offer no flex whatsoever. There are 3 holes in the sub chassis at each of the four corner locations where those angle iron brackets could have been located. The top of the sub frame of mine sits just below the main frame. It appears there has been some mischief about both rear gearbox mounts on the subframe and I have deduced that there were fatigue cracks repaired by removal of offending portion of sub rail and a piece of formed angle iron inserted under, with a washer to pack it up to original level. On that thinking the engine mounts may have also cracked through, prompting the timber repair.

On Doug's recommendation I have just obtained a copy of "Benzine Lancers' by Rod Dux which is about the mechanization of the Australian Imperial Force. When war was declared the force had zero vehicles to it's name and with the ever loyal colony eager to come to the empire's aid a contingent was put together. All up 130 odd new and second hand trucks were purchased of which only 6 were Thornycroft and it can be reasonably be presumed that these were the early J. Interestingly the very first shot fired in the war was on a German ship which blundered into Melbourne's port - so that was 6 new Benz's to swell the list! The concept that this model was a prototype or experimental is not so silly. While Thornycroft had used riveted folded steel chassis in cars and light trucks with success this was a step up from 2 1/2 tons to 3 1/2 tons, and their first attempt at worm drive. Putting the front axle shackles at the front wasn't a success as the rear spring hanger was not up to the job and the arrangement did not lend itself to the normal arrangement of fitting tow hooks. The civilian J did not have tow hooks however a photo in the Dux book of the J's sent from Australia shows straight tow hooks bolted to the chassis rail and it could well be that the 'modified hooks' mentioned in Tommo's thread could in fact be these. The AIF collection of trucks was a real mish mash of makes and when they eventually (after service in the middle east) reached Britain they were swapped over for a standard WD fleet. The Australian mechanization was intended to be fully in lock-step with the British and since I don't recall the entire specifications for trucks being put on this forum here is the version as it was used by Australia. However, bear in mind that the War Office subsidy specs kept changing. War Office SPEC.pdf

I was mistaken with the gearbox case and fooled by the silver paint;- it is steel, with a lathe turned finish. More details around the petrol tank. The right side member must be original as it is shaped to take the hand brake mechanism. Nice filler and the petcock can be restored. The gap under the fixing straps must have held something, not the seat as the tank is too lightly fabricated to take the weight.

While the identity of this chassis is now certain there is much head scratching as to the specification. The only stamped numbers found so far are a 'J' on the left swivel hub and 'J04" (what could this mean?) on the right one. Has anyone seen the unique gearbox with circular aluminium case like this one any where before? Doug has previously scoured the archives as far as correspondence allows, however as Ben has noted on his BT thread it appears a physical search can turn up items that have gone unrecorded. Any leads to literature and L4 engine parts would be most welcome.

The left stub axle has a 'J' stamped on it. Kingpin brass covers missing.