Runaway trains

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By David French

runaway trains

Recent events in the news regarding runaway trains have provided an opportunity to highlight one of the realities of the invention and patenting process: It is not always the original invention that is most important for commercialization. Surprisingly often, it is the follow-up improvements that make the difference. Levering recent events, here are some historical precedents that demonstrate this point.

Recent news articles have disclosed that the incidence of runaway train cars is larger than the statistics reported by the Transportation Safety Board. To be fair, the TSB has posted on the Internet all reports on railway events involving runaway cars. It’s just that their statistical summaries have not been acknowledging runaway events when the cars did not crash or cause any damage. Apparently, more than 300 such lesser events in this category have in occurred in Canada in the last ten years.

This is reminiscent of a situation that existed in the mid-19th century until some very important inventions were made. Runaway trains were a big problem until George Westinghouse came up with his innovations in railway-braking systems. This is an excellent example of progressive inventing.

Up until 1867, railway cars were braked manually by rotating wheels that can still be seen, now usually located on the end panels of such cars and sometimes positioned vertically and near the top of a railway car. These wheels were turned to mechanically lock the brakes by brakemen who had to leap from car to car in order to do the job. Not my kind of work.

In US patent no 88,929 issued April 13, 1869 (Reissued as patent RE5504 or here on July 29, 1873),  George Westinghouse proposed that brakes on a train be actuated by compressed air supplied from the engine. Engines up until then had power actuated brakes, typically applied through steam. But braking just the engine on a multicar train is a very inefficient way to slow down an entire train. Westinghouse’s idea was to pipe compressed air produced in the engine back through all of the cars, arranging for the compressed air to actuate brakes on each individual car  from the control center of the locomotive cabin.  This was the Straight Air Brake.

A feature of this invention was that the hose couplings between cars, which met at right angles, were capable of breaking away without being damaged if the cars were separated. On separation, valves in the  exposed coupling ends would automatically close and seal-off the open hose ends.  This ensured that the pressure in the hoses coupling  the remaining cars to the locomotive would not be lost, preserving braking control over the part of the train still connected to the locomotive.

This new concept was definitely better than what existed before and worked well as long as all of the cars were connected together and linked by the single pressurized air hose. But if, through some violent action possibly due to uneven rails or excessive speed, a car were to uncouple along the length of the train, the air hose would break and the section of cars no longer joined to the engine by this umbilical cord would then run away until they were no longer on a slope or became derailed. Runaway trains in this era were endemic.

Then, as so often happens when a good idea is announced — and this is the object lesson of this posting — a major, indeed an extremely important improvement was made in the air-brake system. Again, it was George Westinghouse who presented the new idea. Essentially, all of the cars in a train were to carry individual pressurized air tanks containing enough air under pressure to apply the brakes on each associated car to the limit of locking the wheels if necessary. Then a pneumatic hose was connected back from the engine through all of the cars providing air at an even higher pressure to a valve that also connected to the individual air tanks on each railway car. As long as high pressure air was being supplied down the train from the engine, all brakes were held in the “off” condition. But if either the train engineer reduced the pressure in the line, or cars were to break away from the train, then this “brakes-off” pressure signal supplied by the hose would disappear and the pressurized air in the individual tanks on each car would apply the brakes on each car.  This became known as the Automatic Air Brake.

This system worked very well, and is in use, in principle, today. George Westinghouse obtained US patent no. 117,841 dated August 8, 1871 (Reissued as No. 5,506, dated July 29, 1873) on this concept. In July 1969, the Westinghouse Air Brake Company was incorporated, an entity that is still functioning today.

George Westinghouse went on to make 27 more patented inventions in the field of train safety between 1870 and June 3, 1913, when the last patent in this category was issued. Meanwhile, as a consequence of the Crash of 1907, Westinghouse lost control of Westinghouse Air Brake Company and a number of his other important corporations. This is also not an unusual precedent for pioneer innovators.

The relevant message is that the first invention made in a new class of technology is not necessarily the most important. Indeed, we have another similar example in respect of the telephone.

Alexander Graham Bell, who patented the telephone in 1876, did so on the basis of two microphone designs, neither of which was satisfactory to a degree that would have supported the telephone industry. One was a dipping wire that extended into a container of acidic water solution. The wire was connected to a diaphragm which vibrated when stimulated by a human voice. The dipping of the wire would vary the resistance for an electric current running through the wire into the water solution. This variation in current was a signal that could be used to activate an earpiece in a not-very-distant telephone receiver. The other microphone was essentially a design similar to the modern magnetic loudspeaker, but used in reverse. Vibrating a wire coil in a magnetic field generated a small electric current that was then sent to a remote telephone receiver.

Neither of these microphones was capable of supporting signals, telephone signals, over long distances. However, in the year following the grant of the Bell patent, Thomas Edison came up with the carbon microphone. Edison invented the carbon microphone in order to make recordings onto wax cylinders. When Bell and the people working in the Bell Telephone Company that he had founded (now American Telephone and Telegraph) learned of the Edison microphone, they quickly acquired a license to use it in telephone applications. After that, the success of the AT&T telephone innovation is legend. That original Bell patent has been rated as one of the most valuable patents ever issued. Congressional hearings were held over whether it had been properly issued. In its lifetime, it was asserted in litigation over 600 times.

Continuing the theme of this posting, AT&T went on to make a number of remarkable improvement inventions in the operation of a telephone system. These included the switchboard, the rotary dial, and eventually the famous “hunt and sweep” automatic telephone switch that transmitted calls through telephone exchanges for over 80 years. The carbon microphone itself was in use in telephones for over 100 years. I remember as a child unscrewing the mouthpiece on the old dial telephones to find a somewhat heavy circular disk inside that could be easily shaken out. After examining it, I carefully replaced it, knowing that my parents would want the telephone to still work. That was a carbon microphone.

In conclusion, it can be safely said that whenever a breakthrough invention occurs, there is likely to arise a long string of improvements which, in themselves, can be so substantial that some of the improvements are more valuable than the basic invention. Of course, if the patent associated with the basic invention is properly drafted, it will dominate and no one will be allowed to use their improvement without permission from the Master Patent owner.

Every inventor aspires to invent a Master Patent, but this seldom happens.

David French is the principal and CEO of Second Counsel Services, which provides guidance for companies that wish to improve their management of Intellectual Property. For more information visit

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