The History of PASMA

A history of mobile access towers and PASMA the trade association that champions them

Brief outline history

Originally designed just after the Second World War in the US, alloy towers were imported into the UK until the 1950’s when production started under licence in the UK. During the 1960’s and 70’s a number of companies entered the manufacturing market and thanks to financial and legislative pressures the hiring of towers expanded rapidly to create an annual sales market worth over £12,000,000 in 1985. PASMA was founded in 1974 and for the first few years of its life functioned as a straightforward trade association. However, with the explosive growth of the hire market and the widespread use of this ubiquitous product the need for user training rapidly became apparent. In response PASMA developed its user training course and this coupled with legislative changes such as the HASAWA has led to an explosive growth in the demand for PASMA training. On the back of its training course PASMA has developed its role in the industry to become the voice of the industry and the go to organisation for anyone with a question about working at height safely.

The early years “necessity is the mother of invention or was it?”

The 2nd World War has often been credited with bringing about the development of mobile towers made out of aluminium. The writer was told when he joined the industry in the 1960’s that aluminium towers were developed during the 2^nd World War when there was a need for easy to move aircraft maintenance structures to get scarce aircraft turned around and back into the air as quickly as possible. He was also told that they had then been adapted to fulfil a need for easy to assemble radio transmission towers. The equipment used for these applications needed to be light, quick and easy to assemble and dismantle, it also had to be easy to transport to a new location at short notice as forces advanced across Europe. Towers made of steel had been around for most of the 20^th century but these were heavy, difficult to move and required skill to build them correctly. The development of these products he was told took place amongst aviation companies in the US where materials like aluminium were relatively easy to source. Welders were not so easy to source however which is why jointing methods such as swaging were investigated. Being made in the US at this time the products were made to imperial dimensions using an off the shelf imperial tube size of 2 inch outside diameter with a wall thickness of approximately 1/16^th of an inch.

However, despite our best efforts, we have no written or photographic records of any of these military inspired products. Were they just a myth spread around by imaginative salesmen or is the story true but undocumented? PASMA would welcome any information that might shed light on these early years.

Brian Madden to whom we are indebted for so much of this early information adds

“I have seen no evidence in USA that military aircraft during WW2 were maintained using aluminium structures. It may be the case, but not to my knowledge. The aluminium towers for temporary military communications were, I think, developed after WW2. At the same time, during the 50s, there was a huge demand for temporary towers for non-military microwave telephone communications. This was the developing technology at the time. A.T & T was the big player. The aluminium towers were erected in several locations on a trial-and-error basis, and antennae were moved up and down the tower to find the best position and height for the definitive microwave path. When this was determined, permanent (steel) towers were built in the best locations and to heights as determined in the testing.”

Addressing the question about towers being developed by aviation companies Brian goes on to comment

“I have no evidence that US aviation companies were involved in developing the aluminium tower products. Welding was the basic process, and there were aluminium welders available, but it was a slow and expensive process, and quality depended on the skill of the welder, and was difficult to check. It was well known that welding of aluminium introduced a weakness in the material in the heat-affected zone (the HAZ effect). Consequently other methods of jointing were researched. In the 50s, UpRight Scaffolds USA developed an epoxy bonded jointing system, which was carried out at room temperature. This produced excellent joints, but the quality control of the system was problematic. In the 60s, the same company developed a cold-forming process to swage the aluminium tube to the aluminium joints. This was also carried out at room temperature, thus avoiding the HAZ effect”

So, were the WW2 stories just wishful thinking? What we do know from documented evidence is that Wallace (Wally) Johnson produced a prototype aluminium tower for home use in 1946 and filed patents for his design in 1947 going on to set up a factory and business called UpRight Inc in California. This is documented in detail in his autobiography “The Uncommon Man in American Business” published in 1966 by The Devin-Adair company in the USA. The Devin-Adair Company 1966 Wallace Johnson Article. PASMA and the writers would like to thank Brian Maddern formerly of UpRight for supplying a copy of this book. In his book Wally Johnson tells of a request from a neighbour over the Christmas holidays in 1945 for a better way of decorating his house. Being at a loose end over the holidays he drew up the basic design that was later to become the UpRight Stairtower. By Spring 1946 he had applied for a patent and by February 1947 had built a factory and started delivering finished product. In 1948 he heard about the US Army Signal Corps wanting two quick erecting 204-foot (62m) towers for tracking missiles and adapted his product to fulfil this. So, is this how the stories about military use started? Once again, we would welcome any information that would shed more light on this era. Wally Johnson was a man of many talents as in addition to designing towers and writing an autobiography he went on to become the Mayor of Berkeley California in 1963.

One other thing that we learn from examining US patent applications of that era is that in 1957 Werner, an established US ladder manufacturer, applied for a patent for an aluminium tower (see illustration below). So, by the end of the 1950’s we can be confident that there were two competing manufacturers of aluminium towers in the US one on the East Coast and one on the West. Can anyone shed more light on these early developments?