By adding a base plate it makes for a stronger and safer child play model. It also gives Lesney a better platform to cast text, in particular Caterpillar for which they required licenses. Cost wise once a mould was made the benefits speak for themselves of producing 1 component of base/blade instead of having two moulds for blade and base plate. They still had a second mould for the body but the saving here was it was the body was that from the 8d Caterpillar Tractor.
The manufacture of the 18d/8d base plate would have been cost effective too, given it almost the same and easy to duplicate from master pattern with the exception of the text to clearly distinguish the tractor from the dozer and of course the blade.
Malibu wrote:hi bert,
thanks for the explanation and the pictures.
I wonder why they did it like this and not like the other castings befor.
Stephan
Hi Stephan,
I would think it would be to speed up the manufacture process, in particular the painting. Previously the 18a, 18b, 18c blade and body were painted separately, and then stored before fitting.
The 18d Caterpillar Bulldozer however once the body and base were fettled they were then riveted together and then painted. This means one operation for painting and less storing of painted parts. Then it was off to get the tracks fitted by opening the gap near the single stud and blade arm.
There were possibly two ways the final assembly was done.
One is to fit the rollers and axles then have them riveted and followed by stretching the tracks over the rollers.
But a safer way would be to fit the rollers and axles, then pull the tracks over the rollers. The slight pressure from the rubber tracks would keep the rollers and axle from falling off, and then they could be riveted. This method means rubber tracks are not flopping about while they are being presented to the axle end riveting machine. The operator simply puts completed models into a tray, after axle ends are rounded over, they are then boxed and sold and 50 years later happily collected, discussed, displayed and even repainted.
Unlike the 18b and 18c where we find body and blade two tone coloured models it does not apply to the 18d because of riveted base to body prior to painting means all one colour.
Another item of interest it that its big brother the king-size K3a Caterpillar D9 Dozer was cast without the hook but can be found with the hook aka K8a Tractor load. The 18d body is essentially the 8d Caterpillar tractor body with the hook found on every model. This was another cost saver by only needing one mould type for the body component for two models.
Bert
Note to Glenn,
I typed the above up before heading off to work and on getting home this evening I now see your post which gives a little different idea. Rather than add or alter the text please let us know if you need photos to clarify.
This was one of the models I was working with Kwakers on before his passing. We both had what we believed was a combination of a more accurate listing of this model, something I must get back to in the next 30 years.
