The Crowbar Circuit

Even good operators could not do anything when static was so strong as to blot out all trace of a spark signal, so Professors Pickard and Proctor set up a huge fixed loop antenna and tried copying on that. They also built a large rotatable loop, which could be rotated about a vertical axis and also tilted about a horizontal axis, so that – as seemed to be the case – if the waves from Europe, meeting the cliffs, were tilted upward, the loop coils would meet them at best position for extracting their energy. About six fixed loops were built, one for each station to be copied on long wave, and also for the Eilvese low power code transmissions. The loops gave much better results than the long horizontal wire antennae.

But still, this was not enough, so the balance idea came into play. Pickard’s idea of grounding the loop to serve as a vertical was adopted. At first it was grounded to a counterpoise. One evening, the boys were trying hard to determine the best conditions with the apparatus in a tent with wooden top and canvas sides, and had finally gotten a signal – static ratio of about one to ten. The “balancing” was very broad, the resistance in series with the ground lead could be varied over a wide range without making much difference in results, whereas in a good balance there would be a certain value of resistance which would be somewhat critical.

Someone suggested a direct ground be tried. The only thing at hand for this purpose was a huge crowbar. This was hammered into the ground, and connected to the vertical wire circuit. At once, a much better balance, and signal to static ratio was had. Proctor, feeling frisky at the time and having absorbed several quarts of champagne, and acting on an impulse, went out to the crowbar and urinated. Someone from the tent shouted, “That’s the best balance we ever had, it’s ten to one!” For several hours this remarkable condition persisted. As a result, pipes were driven in the ground and the entire staff preserved their hourly urine for pouring into the ground. It is a literal fact that on this humble base rested much of the U.S. Navy’s success in copying signals from Europe during the War. This circuit, for obvious reasons, was known thereafter as the “Crowbar Circuit.”

Direction Finders and Convoys

The use of direction finders changed radically during World War I, when the success of the German submarine campaign brought about the desperate allied shipping situation in the Atlantic. All destroyers available were fitted with the Model SE-995 direction finder to locate enemy submarines, to effect concentrations of hunter-killer operations and to assemble and escort convoys in thick weather. An installation at the U.S. Naval Base at Brest, France, permitted surveillance of the German submarines concentrated in the Bay of Biscay. The extensive, uninhibited use of radio communication by the German submarines, unaware of the Navy’s direction finders, made it possible to divert allied convoys to avoid them. This procedure was highly successful.

The serious allied shipping losses experienced early in the war led to action to  reduce vulnerability to the German submarine menace by expediting the entry of ships into United States ports, particularly during bad weather. To provide navigational guidance to the ships, the Navy installed a number of temporary direction-finder stations, located between Maine and Cape Hatteras.

50th Anniversary of Navy Radio at Winter Harbor Naval Base 1967

Naval participation in the 1917 war was limited for cryptanalytic development, but interest was stimulated.

By NCVA: David White