Pneumatic Door Closers

If there is one area that Britain triumphs over all others (aside from archaic systems of government) it is the area of Pneumatic Door Closers. The PDC industry is one that holds a particularly fond place in British history. It is possibly the finest British invention since feudalism. And one that has held the hearts and minds of millions of Britons for hundreds of years. From their humble begins as a crude form of transport to today's world coverage of the PDC championships at Earl's court, PDCs have always been at the centre of British culture.

I will start by stating that I have had a fascination with PDCs since the age of 14. During my time at school my friends and I would stand and watch their operation for hours on end during break time. My favourite is the traditional Centurion 2, but I do hold a lot of respect for the new Briton 2000 series that have become so popular in the 1990's (at the end I will be reviewing the NEW Briton 2007S).

In 1783 the first PDC was made in response to the Duke of Brixton's desire for a rapid and fuel-efficient form of transport. Many designs were offered, but the Parallel Ground Initial Vector Acceleration System, caught the Duke's eye. The principle behind the PGIVAS was simple; the passenger would board a small carriage. The carriage would then be attached to a launch arm. Once the passengers were settled, the launch arm would provide a force that would accelerate the carriage towards the destination. Once free of the arm the carriage would gracefully sail towards the destination parallel to the ground, before touching down and allowing the passengers off.

To save money the carriage was a simple bench and the launch arm an old door taken off Brixton Castle. Only the means of providing the force needed to be constructed from scratch. This was solved by gluing a rod to the top of a baked beans can lid, putting a rubber seal around the edge and allowing it to move inside the (empty) can. The can would be charged by applying pressure to the rod and discharged by stopping applying pressure to the rod.

Unfortunately the Parallel Ground Initial Vector Acceleration System failed to work. Primary among its problems was a neglect to consider the force of gravity, which firmly refused to allow the carriage to move parallel to the ground and the connected problem of injuries caused by rapid acceleration towards the ground.

However some good did come of the affair. Once the PGIVAS had been disassembled, it was realised that the castle door would now close automatically. Thus the PDC was born.

I was lucky enough to receive a preproduction model of the NEW Briton 2007S. I have put it through a series of gruelling trials and will now give you the verdict:

The Briton 2007S builds on the foundations of the chart topping 2007, undoubtedly the finest door closer on the market today. The 2007S features the standard pneumatic system that all Briton 2000s have, but it has been fine tuned to provide a quick, but quiet pressure to the door. Externally the 2007S is much more sophisticated than the 2007 with a brass finish and a shorter, sleeker closing arm. This gives the impression of a sleeker, sharper unit than other offerings in the class. The designers have however gone out on a limb and used the older Romeo style popular in the 60's and brought to fame by the above-mentioned Centurion 2. It would be nice to see the Romeo style come back into favour, but I fear that modern offices will not be accommodating for such a dated style.

Now I will go on to more practical aspects. What's it like in the real world? I first tried the 2007S on a light 20kg 'sandwich' door. After adjusting the unit to about 20% the door closed in less than 4 seconds, with almost no noise. The door accelerated to 140m/s during the first 2/3 of the cyc

le then slowed to 1 mph for the final 33% with a closing speed of 10[degrees] per minute. The final stroke applied a closing force of 5,103N. This is rather more than the average PDC, and I thought maybe a little dangerous. If a small child were to get caught in the door during the final stage ve[*] might sustain injury. To test this theory I acquired a small child and placed him next to the doorframe. I was pleased to be proved correct when the door did crush the small child. Indeed the door caused so much damage poor Tim may never walk again.

I then tried the 2007S on a larger door, a 50kg glass unit. This time the performance wasn't as high. The door took more than 10 seconds to complete the full cycle. Increasing the pneumatic tension carburettor, lowered the time to 7 secs, but introduced a high pitched, and wholly unacceptable, whining. As expected a heavyweight 80kg oak door proved too much for the 2007S, failing to complete the task unless the door was closed to 1/2[rads] manually.

In conclusion I must say that the Briton 2007S is a very fine PDC for a small door in a corporate environment, preferably one where small children of a crushable nature are not abound. However the 2007S flounders under pressure and cannot be used for the mid and large classes of door. The exterior is stylish and well constructed, but the classical styling may not suit all offices. Overall the Briton 2007S is a good buy, but only if the 60's styling is acceptable.

I hope to see you all at Earls Court this weekend for the PDC championships.

[*]- ve shorthand for 'he or she'

[Copyright Ross Newell 1997]