Tractor Safety and Quiet Cabs

In the 1970s, Government legislated to make safety cabs and roll bars mandatory for new tractors destined for the U.K. market.  In the run-up period, weather cab makers were encouraged to produce safety cabs or roll bars for pre-existing tractors. With an estimated 250,000 tractors requiring such structures, we soon had a strong demand from hillside farming areas where the risk of the tractor overturning was greatest. Hundreds of Welsh and West of England hill farmers had been injured or killed over the preceding decade.

Cab-Craft produced the first safety cab for International Harvester tractor dealers in the late 1960s. The frames were tested and approved for several livestock farmers I.H. tractor models at the N.I.A.E. testing station at Silsoe, Bedfordshire. The test involved a swinging pendulum weighing up to a ton striking the cab frame bolted in situ on a tractor. The skill came from anchoring the cab correctly to the rear axle. The cab frame had to be fabricated with a frame designed to 'give' up to 12 degrees when struck by the swinging block. Too strong and the fixing bolts would shear off, too weak and the frame would have too much distortion.

In the early days, there were several trips to the test station to finally get a cab passed. One of the first safety cabs we produced went to a Welsh hill farmer in Newtown. Soon after delivery, we had an urgent call from the dealer asking for a replacement. Why? Their customer rolled his tractor 900 foot down a hillside when the farm track collapsed under the wheel on the downhill side. The tractor wheels flew off early in the rolling period but the driver stayed in his seat as instructed on our label. He was able to walk away from the wreck uninjured, but badly shaken and went back to work the next day.

The insurance company agreed to the immediate replacement of the tractor provided it was supplied complete with a Cab-Craft safety cab. The farmer sent us a thank you letter, complete with a picture from the local newspaper with the headline 'Safety Cab saves Newtown farmer's life'. There were many such anecdotes over the following years, but even today, tractors overturning remain high on the list of farming fatalities.

This proved to be the biggest problem we ever had to face. Placing a cab on a tractor not designed for a cab resulted in often deafening noise levels at the driver's ear as vibration and transmission tunnel noise was amplified inside the cab.

To achieve the maximum 75 decibel test limit, not only had the cab roof and walls to be well insulated, but so had the mounting brackets, which had to be rubber cushioned. All the tractor surfaces insulated.

Later, the maximum was reduced to 70 decibels.

Cab-Craft negotiated a multi-million pound contract to supply all UK models of their 40 and 60 hp. tractors complete with safety quite cabs, including the supply and fitting of the noise deadening material, and noise testing each tractor within our own factory before shipment to the dealer.

We rented a new factory in Shaw Lane, Wolverhampton and set-up a dedicated production line for this contract. Each week, lorry loads of tractors came from Massey's Banner Lane plant along with lorry loads of cabs from our Four Ashes factory to the Shaw Road factory, where we employed 35 people for the fitting operation. The contract was to last 3 years, until new models were brought on stream, developed with an integral quiet cab. It was at this time that Massey ceased UK tractor manufacture, eventually transferring all production to their factory in France.

Fork Lift Truck Cabs with Falling Object Roof Protection/ROPS

We enjoyed a substantial amount of business making safety cabs for fork lift trucks. The safety legislation introduced for these vehicles was called FOPS/ROPS (falling object protective structures with roll over protection). We developed, tested and made FOPS cabs for Coventry Climax, Henley, Lansing Bagnall and others, with roof structures capable of protecting the operator from death or injury when unstable loads dropped off the raised forks whilst removing materials from high racking.

The cabs also had ROPS structures as fork lift trucks were prone to turning over when manoeuvring on slight slopes outside of the warehouse, particularly when the loaded forks were raised above head height. Again, we were pleased and proud to place our expertise at the disposal of manufacturers when it became politically correct to save lives and prevent injury.

Rollover Protective Structures for Large Crawler Tractors and Wheeled Loaders

Soon after farm tractor rollover protection became law, we started receiving enquiries from earthmoving vehicle manufacturers and distributors for similar cabs for crawlers and wheeled loaders. The move was led by insurance companies who were insisting on similar levels of protection for drivers.

This would prove a very difficult task as there was no standard in the U.K. or Europe, for ROPS for heavy earthmovers, some weighing in excess of 45 tons. John Barker reached an agreement with a USA manufacturer of ROPS cabs for Komatsu and Caterpillar earthmovers, covering a wide range of models used in the U.K. These were built to S.A.E. standards and satisfied our customer's needs.

John and I visited the Medford Company in Oregon and negotiated a licence agreement covering the whole of the U.K. and Europe. We promoted the availability of ROPS cabs for earthmovers, and with the agreement of Mitchell Cotts, set-up production facilities in a new unit adjacent to our Penkridge works.

The ROPS frames were made of large, thick-walled tube and the finished product could weigh upwards of 2 tonnes. The mounting points were a critical dimension so we developed assembly jigs to ensure each cab would exactly fit the machine. We purchased rotating welded assembly positioners to enable our Lloyds Class 1 certificated welders to place thick welds laid at the correct level.

In the U.K. we started supplying ROPS cabs to quarrying and mining groups, and soon saw examples of how our cabs saved lives when these giant machines either overturned or had a large boulder drop on the cab roof. We were the only European company with this capability and were soon exporting to Germany, Scandinavia and other northern european countries. Komatsu, the Japanese market leader who competed head-on with Caterpillar, had long been one of our major customers for weather protection cabs.

As with tractor cabs, within months, we were being asked to provide quiet cabs, and were able to use our farm tractor noise suppression know-how to achieve this. One of the techniques we employed was the coating of the internal metal surfaces with nylon flock, producing a velvet-like surface. These particles were applied after coating the surface with resin, and applying an electrostatic charge to the cab. This made each 2.5mm long nylon particle adhere at a ninety degree angle to the surface. In addition to deadening the sound, it also gave quite a luxurious appearance. We went on to offer this product in all our cabs, and set-up a separate cab flocking area in the paint shop, to avoid contamination.