Karhedron Posted July 30, 2020 Share Posted July 30, 2020 (edited) 1 hour ago, Paddy said: Just a quick side question on this... is the simple white livery with “U D” branding used on some early tanker models real or just “modellers” license? Assuming you are talking about the livery I am thinking of, that is the post-war United Dairies livery. You can see a couple of them here at Halesworth in the late 40s when nearly new mixed in with some older, dirtier example. United Dairies had a huge range of liveries, sometimes it seemed like every batch of tankers built for them was painted in a different version of their livery. Edited July 30, 2020 by Karhedron 2 1 Link to post Share on other sites More sharing options...
Paddy Posted August 1, 2020 Share Posted August 1, 2020 Thanks Karhedron. Amazing, I assumed that livery was fake and just a reflection of simplistic “toy” decoration. Many thanks Paddy Link to post Share on other sites More sharing options...
Karhedron Posted September 15, 2021 Share Posted September 15, 2021 On 12/04/2020 at 19:03, jim.snowdon said: The Milk Marketing Board assumed control of all the rail tankers in 1942 and as and when they needed repainting, they were put into an overall silvery-grey livery with just an embossed plate in 4" lettering indicating the ownership. It wasn't actually repainting. The pre-war milk tankers were built with a layer of cork lining as insulation between the internal tank and the mild steel outer skin. After more than a decade in service, this cork was starting to perish on the oldest tanks. As necessary, tanks were refurbished which involved replacing the perished cork with glass wool as insulation. The tanks were then reclad with aluminium. Since aluminium does not rust the way steel does, they were frequently left unpainted. So it wasn't a silver-grey livery that was applied, it was just the bare aluminium of the new cladding. 1 3 Link to post Share on other sites More sharing options...
Karhedron Posted September 15, 2021 Share Posted September 15, 2021 On 13/04/2020 at 22:04, jjnewitt said: I still have yet to be convinced about the 'pooling' of milk tanks into the 60s. I don't see the random pattern of milk tanks that you'd expect in such situations. You see a lot of tanks belonging to a certain dairy working to their creameries. As I said earlier there's a difference between organising the distrubution of milk by rail to having responsibility for the milk tank fleet. Part of the reason for this was that in the early days of tanker traffic, United Diaries and Express Dairies implemented different (and incompatible) connectors on their tanks. This led to a VHS/Betamax situation where certain tanks could only serve certain dairies. I don't know if the situation continued into the 1960s but it would be one possible explanation as to why tanks for certain dairies were allocated to certain routes rather than being totally randomised. 1 1 1 Link to post Share on other sites More sharing options...
RMweb Premium Compound2632 Posted September 21, 2021 RMweb Premium Share Posted September 21, 2021 Not a milk tank livery question but following on from @Karhedron's comment about recladding with aluminium in lieu of the original steel, with glass wool replacing cork insulation, a question, if I may, about how the tanks were constructed. This came up in conversation at our club meeting; as milk tanks are "not my period", I for one was stumped. The understanding is that the inner tank was glass or glass lined; or possibly vitreous enamel. Was this inside a steel tank? How, in fact, were they built? Link to post Share on other sites More sharing options...
Nearholmer Posted September 21, 2021 Share Posted September 21, 2021 (edited) From what I can understand from a contemporary magazine article: - inner tank was vitreous enamel finished; -- then cork insulation; - then an outer skin of mild steel. The biggest question I have is about the inner, because I struggle to believe that it was made as a unit, then VE finished, I just don't get how that could be done, which poses questions of joints/seams and how they were sealed. I wonder if there is some "lost art" in this, because before stainless stell became widely used, there must have been other large vessels in the food industry that needed to be kept hygeinic. PS: This patent suggests that whatever the initial method of VE coating the interior of tanks, it wasn't perfect https://patents.google.com/patent/US2229526A/en PPS: Another, slightly earlier patent for an improved method https://www.freepatentsonline.com/2070368.pdf From what I can find, the process was first made viable (if not perfect!) c1930, and a US firm A O Smith seems to claim that they pioneered it when large-scale brewing recommenced after prohibition. Edited September 21, 2021 by Nearholmer 1 Link to post Share on other sites More sharing options...
Karhedron Posted September 22, 2021 Share Posted September 22, 2021 (edited) As far as I am aware, the inner tank of the early tankers was of metal construction, probably steel. The "glass lining" was not really glass in the conventional sense. Rather it was a coating of vitreous enamel applied to the inside of the tank to provide a smooth continuous surface that would be easy to clean and sterilise. The vitreous enamel was applied as a paste containing ground glass to the interior which was then heated until it fused to form a smooth coating. I haven't found details of how this was achieved. It would take a large kiln to fit a 3000 gallon vessel so maybe it was done with a blowtorch? I am just speculating here as I don't really know. Wikipedia states the fusing point of VE is 750-850 degrees-C which is hot but a lot lower than the melting point of steel. Although early tankers famously proclaimed they were "glass-lined", they were not popular with the railways. The VE was comparatively fragile and did not take kindly to be shunted roughly. Some time in the 1930s, it seems to have been phased out and tanks were instead lined with stainless steel. Express dairy tanks sometimes carried logos such as "Staybrite steel". The last record I can find for glass-lined tanks was the batch built for the IMS by the GWR in 1936. Later tanks may still have been glass-lined but I cannot find photos or records to indicate one way or the other. Edited September 22, 2021 by Karhedron 2 Link to post Share on other sites More sharing options...
Nearholmer Posted September 22, 2021 Share Posted September 22, 2021 44 minutes ago, Karhedron said: It would take a large kiln to fit a 3000 gallon vessel so maybe it was done with a blowtorch? I am just speculating here as I don't really know. Wikipedia states the fusing point of VE is 750-850 degrees-C which is hot but a lot lower than the melting point of steel. This was the bit that intrigued me, and if you look at those patents I linked to, I think one shows a huge oven, into which the entire tank fits. If you think about a common or garden domestic bathtub, that is a fair old lump of iron to raise fusing temperature, and that was ordinary stuff ”back in the day”. I don’t think this has anything to do with milk, but my surmise is that these big tanks are of the same general kind. https://www.warwickshirerailways.com/lms/lnwrcs2131.htm 3 Link to post Share on other sites More sharing options...
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