On clear days we see the long white contrails of jet aircraft stretching across the sky. Some seem to cross near to one another. We know the aircraft won’t collide. All aircraft strictly adhere to a height and course set by the air traffic controllers on the ground below.
In addition they are equipped with that most significant safety device, radar. The radar pulses sweep the skies ahead, picking up other aircraft, as well as storm clouds and mountain tops and reflect their presence back to the screen in the cockpit.
Out at sea, on the darkest night, the navigators on the bridge can peer into the display unit and see the bright-orange reflections of other ships in the area, as well as promontories and lighthouses, and see how far or near they are.
As long ago as 1889 the German physicist Heinrich Hertz showed that radio waves could be sent through the ether, rebound off solid objects and be reflected back to the source. Over the following decades others worked at understanding and developing the phenomenon.
By the 1930s its capacity to recognise aircraft and ships gave it a pivotal role in the military sphere. The major powers worked at developing technologies that made it more sophisticated and adaptable.
As the second World War approached great efforts were made to find better resolution and portability. The acronym radar was coined for the term “radio detection and ranging”.
During the air raids and aerial battles over Britain and Western Europe radar played an essential role in alerting defences to the approach of enemy aircraft.
Likewise, as enemy ships manoeuvred around one another at sea, the use of far-ranging and reliable radar became essential.
When the war ended the system had become established as a much-desired safety system for aircraft and ships.
However, it was still a developing technology, cumbersome, with limitations. It was fault-prone. Fitting and maintenance were expensive.
At marine level, the Marconi company made admirable efforts to advance and refine the sets it was installing on merchant shipping.
By the 1950s it was making one of the most effective and advanced of its kind, called the Mark IV.
Radio officer
I first saw this remarkable model in Kevin Street College of Science and Technology in Dublin where I was studying for a radio officer’s certificate (second class).
We stood in a semi-circle, peering with some awe into the complexity of cables, wires, valves, capacitors, resistors. It seemed to sizzle and vibrate with high-power and high voltage. Not a place to poke a careless finger.
Our instructor, Mr Blennerhasset, impressed on us that this costly piece of equipment had to be treated with the utmost care and respect.
The next time I saw the Mark IV was on my first ship, the Amra, a deck-passenger vessel that plied the Arabian Sea between Mumbai and the East African ports of Mombasa, Dar es Salaam and Zanzibar.
One dark night while traversing the hazardous seas between the African mainland and the island of Zanzibar the radar was in continuous use.
Then, to the distress of the captain, it went off tune. Curved, swirling yellow lines replaced the echoes of the coast.
He immediately sent down for the chief radio officer, Mr Bourke, He was in the first class bar, drinking gin and, according to himself, making some headway with a lady passenger who wore a backless dress of alluring display.
He came up in a vile temper, throwing aside his white tropical uniform, wrapped a towel round his midriff and ordered me to haul open the heavy door of the radar hut.
Immediately we saw the needle of the tuning dial swaying back and forward, instead of staying still in an upright position.
The chief reckoned that the sweltering equatorial heat was affecting it.
Smelling of gin and sweat, he squatted in the small space and with tapered, nail-bitten fingers began to adjust the tuning controls. He tried and tried. All his efforts came to nothing. Suddenly he was overcome with rage. He sat down on the steel doorstep and braced himself by holding on to the sides of the hut. He shouted,“I’ll get you, you hoor you”, and smashed his sandalled heels again the tuning unit.
There was a tremendous bang.Then, lo and behold, we saw the tuning needle quiver and return to its steady normal position.
Perhaps one of the many finely balanced components had responded to the violent jolt.
When we scampered down to the bridge deck and looked in the display unit we could see the echoes of the coastlines on either side of out ship.
The captain was pleased. “Jolly good. Solved the problem have you?” “Yes, sir. It was a complicated fault but I managed to put it right,” responded Mr Bourke in his sharp Belfast accent.
The Marconi Company asked that malfunctions of the radar and corrective measures to put them right be reported on. This incident wouldn’t be the subject of any report.