|The new roof
One of Michael’s first projects after he joined was to replace the Richmond Road factory roof. This was the original roof constructed in 1917 as part of National Aircraft Factory No. 2, built in haste to ramp up aircraft production for the First World War. Sopwith Aviation moved into the factory in 1918 and in 1920 it was taken over by Leyland Motors. In 1948, Hawker Aircraft re-occupied the building as a replacement for the closed Langley site and it became the main factory in Kingston when Canbury Park Road eventually closed in 1958. Here he describes the problems encountered during this project.
I joined at a time they just decided to replace the old factory roof. It was a massive area and it was over all the aircraft building that was going on and machining. I was asked to take on this project and the contractor arrived very shortly after I arrived and started to strip the roof. Now there was thirteen miles of timber to be removed plus all the old felt and it was a product known as a tentest board that the felt was lying on that had to be removed. But before you could do any of that we had to close footboard the scaffolding that was in the roof so that the production could go on below in safety, completely free of dust and dirt. So it meant layers of tarpaulin being put down and then the stripping of the roof. And to strip the roof they had railway lines put down and trundled carts along [in the valley gutters].
It was a two year project. And in the process they used a product called Galbestos which was a four-layer, steel protection system but did contain asbestos and it was rolled into the material – later to become a problem. The project then went on, as I said, for two years. Each bay at a time being stripped and rebuilt and it was slightly modified because it was known as a barrel vaulted roof. And we then decided to have flat sloping to the apex. So it meant some alterations with steelwork. Later, after the project was finished, we started to notice some de-lamination of the four layers. In fact it was two and a half layers that were coming away, exposing asbestos material. Although it was tracked into a kind of bitumen material, we could see the fibres.
The manufacturers were unwilling, it appeared, to do anything about it. So we had to engage the company’s legal department, the lawyers and so on, and ended up at meetings in London. And they served whatever notice, legal notice was required, on the company, HHR Robinson. They decided, eventually, that they would strip off all the lose material and re-coat the roof on site. With apprehension, undertook acceptance of that, and the work began. And that took six to twelve months to re-do.
Now, one of the important things about the roof was, that as it was a very old design, going back to the First World War, it had very limited capacity to carry weight. And that was a critical factor in the choice of the material to go on, and the fact that we wanted to raise the level of insulation, and also put a nice lining which was a kind of plasterboard on the inside to reflect the light. The maximum loading that you could permit on any truss was two hundred pounds and the maximum weight of snow was six inches. So you can imagine most winters when it snowed there was panic. And there was many a time when I was actually, during the night, in the factory measuring the depth of snow. Because we did have a night shift, although it was much smaller than the day shift.
On one occasion it reached eight inches and I had to send everyone home and close the place up. The next day, to try and recover because we had all the day shift people coming in, we had to plan a way of recovering the situation because the weight of snow. It wasn’t melting because the level of insulation in the roof meant the heat, where it would previously pass through because there was little or no insulation in the roof originally, the heat wouldn’t pass through and as more snow came it just built up – we didn’t have melting.
So the only way we could solve that problem and get people back safely working in the factory was to have a small gang, properly controlled, listening for any ‘creaking and groaning’ and send them in to remove the insulation panels in the roof. Now this was up to thirty, forty five feet in height so it meant towers and so on. It was a real problem but it did melt the snow rather quickly. We had thought of spraying but such a vast area just was out of the question, so letting heat get through and melting the snow was the answer. And in twenty four hours or so we did get rid of the snow and we were able to reopen the factory for work.