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Modeller Build Logs
Scammell Pioneer R100 |
| By Alex Hill | | Started: | Sep 18, 2004 | | Updated: | Jan 31, 2005 |
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The Scammell Pioneer must surely rank as one of the most charismatic military vehicles. Having been around in various guises since 1927, many Pioneers are still earning a living as show-mans wagons and recovery trucks, so the design can probably lay claim to the title of longest serving vehicle as well.
This kind of longevity only comes from good solid engineering and strokes of genius from the designers at Scammells’ Watford plant and Gardners’ Manchester engine factory. In many ways it was the fitting of the Gardner 6LW power unit to the Pioneer that made the vehicles reputation for soldier proof reliability. The engine featured advanced (at the time) lubrication and injection systems. Combined with Scammells’ transmission and static, non-pressurised, cooling system (hence the ‘coffee pot’ radiator), Pioneers could be expected to give a hundred thousand miles of trouble free running. Most of Gardners’ competitors were struggling to produce an engine that would pass one third of that mileage without at least needing the main bearings replaced. The attention to longevity didn’t stop there. The winch mechanism is something close to a work of art. At a time when a winch was basically an overgrown cotton reel hitched to the vehicles’ p.t.o, the Scammell employed every trick in the book (to be covered in more detail in later chapters) to ensure the winch rope was never kinked or over stressed.
Truly a magnificent machine with a capacity to invoke a sentimental fondness that means there will probably still be a handful of Pioneers earning their living on (or off!) the road in fifty years time when most of the current crop of M.V’s are relegated to gathering dust in museums.
Which brings me to my (hopefully never-ending) quest to build the perfect 1/35 Pioneer. The kit is of course the excellent Accurate Armour rendition of the R100 artillery tractor. In my BLOG I’ll be adding as much detail to the base model as I can, improving those parts which can be improved upon and making one or two changes just to illustrate the differences which were built in during the Pioneers’ production run. Of course an artillery tractor needs something to hang of the rear hitch, so I’ll be adding Accurate Armours’ 7.2’’ Howitzer.
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| Chapter 2 - The Winch | Oct 30, 2004 |
The Winch. It’s one of the features that sets the Pioneer apart. The mechanism was designed for longevity, which it achieves with some interesting, unique features. The main element of this is the automatic cut out. The entire assembly is able to pivot on the chassis against a spring. If the load on the cable exceeds 8 tonnes, the spring is compressed, this acts on an arm, which leads to the fuel pump, thus cutting out the engine in the event of an over load.
The ‘clock-work’ paying on device further protects the winch rope. (AA part AL). This used drive from the toothed section on top of the winch drum to move a set of fairleads up and down to ensure the cable could not be bunched or twisted as it was drawn in or paid out. This was complemented by the pinch rollers which utilised a spring running under the drum to maintain a constant tension when the un-loaded rope was being drawn in, again, preventing twisting and bunching. The last, simplest, point to mention is the drum diameter. By using a vertical spindle, Scammell were able to accommodate a much larger drum. This meant the cable was wound under less stress, thus increasing service life.
The best source for modelling all these complicated mechanisms is ‘Manual of Recovery Part 1. Tractor 6x4 Heavy Breakdown Scammell’ –available from Groucho Publishing. This is a very handy re-print of a 1944 manual for the SV2 Pioneer, but the winch details are the same for the R100.
Which brings me to trying to build all of the above into the kit. It’s a tribute to AA that most of the extra parts needed to recreate all this detail can simply to glued straight on. Only two of the kit parts need a little modification. The mounting bracket for the aforementioned part AL is over simplified and needs replacing. The other part is the drum housing itself (part AK). The right hand side should be scalloped along its top and bottom edge. This is no problem at the top, but when the material is removed at the bottom it leaves a dirty great hole into the area where the winch drum lives. This isn’t something you could correct without replacing most of the housing and the drum itself, which would create all sorts of clearance issues when the rear body is fitted later on. The best compromise I could see was to build in a rounded edge on the inside of the housing. Hopefully, at the painting and weathering stage this can be disguised with a dark shadow, leaving the impression of a scalloped edge and a flat surface on the underside of the housing.
As for the rest; well it’s more brass rod and plastic card. It should be noted that it’s well worth having the cab and rear body temporarily glued at this stage. The only way to ensure that nothing will foul later on is with plenty of dry fitting.
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