This tale is heavily biased towards fault finding on 1960’s Marine radio equipment, however investigations of any type, whether they be research into your family history or fault finding on complex electronic equipments can lead to discoveries or outcomes that were never envisaged when the works commenced. That is certainly the case in this tale.
You dear reader may be drawn to the conclusion that I am a radio anorak, when I state that the marine Medium Frequency (MF) and High Frequency (HF or short wave) transmitters that I sailed with and operated in the 1960’s spoke to me when they were powered up and operated. Other Radio Officers (R/O’s) of that and perhaps even later eras might confirm the truth of what I say.
I do not mean they would say, “Good morning sparks how are you today” or “My word sparks, that was the best Morse code I ever sent” because they had no artificial intelligence built into them and they certainly were not fitted with digital voice cards like many of today’s high end, Japanese manufactured Ham Radio rigs. They did however make very individual and distinctive sounds when they were used.
This “voice” of theirs differed between the various types of transmitter fitted on board ship and between the transmitters made by different manufacturers. Some had a tinny voice as the soft iron laminations of their linear power supply transformers vibrated, some clacked when the keying relays that applied the 1000 to 1500 volts DC to the power amplifier stage were activated and some had a very high pitched whine that was produced by their motor alternators that converted the ship’s domestic supply of 110 Volts DC to 240 Volts AC that was required to power the transmitter. These sounds changed as the transmitters were keyed and varied in loudness according to the amount of power being fed into the ships aerials.
Some transmitters had a voice that combined these various sounds, which I (and others) became familiar with over time, just as a parent becomes familiar with the cry of their own child amongst a group of other children having fun in a playground. It was very easy therefore to quickly become familiar with the sound almost of contentment that came from a transmitter when it was working well and tuned to its optimum power output. (Ok, I put my hands up and admit to being a radio anorak!)
Over the course of a voyage from the UK to Sri Lanka (or Ceylon as I knew it when I was at sea) conditions could and did vary but this could usually be explained by say rain and fog enveloping the aerial system or after a long dry period when salt and sand might accumulate on the aerial insulators. This latter problem was common to conditions in the Red Sea where such changes would occur slowly over time and resulted in a gradual change to the transmitter’s voice but not rapidly enough to cause any real concern.
On Thos and Jno Brocklebank’s SS Mahseer during my first deep sea voyage in 1963 the Chief Radio Officer (R/O) Harry Jefferson and I discovered there was a major problem with the transmitted power levels from all of the transmitters which showed itself whenever the ship was rolling and pitching in heavy seas. The transmitters would change their voice very rapidly, singing a different song as they were keyed. The aerial current ammeters (power into the aerial) also showed very large variations in level even when the transmit key was held down to produce a continuous transmission.
Between watches and at each port of call on the outbound journey, the transmitters were inspected for loose connections or for anything else that could explain the cause of the problem. No matter what we tried or did, we could not cure the fault.
On arrival at Colombo when the ship’s station closed down, Harry and I started from scratch and checked everything that could be checked. All the transmitters were inspected in minute detail. All of the insulators used by the Main and Emergency aerials were checked for damage or cracks. At that time all of these insulators were made from either glass or glazed porcelain material that was easily damaged when the Indian crew allowed gravity to take over when they literally dropped the aerials onto the steel deck. These types of insulator were eventually replaced by the Radio Department with solid plastic insulators that were far more durable and crew proof.
The aerial changeover panel was inspected as were all of the aerial feeders within the radio room. These feeders were removed from their bulkhead insulators, checked for fractures and their terminals cleaned with emery cloth. The copper aerial wires of the main and emergency aerials themselves as well as any clamps and any soldered joints were closely inspected to ensure their integrity.
When all this work had been carried out, the only thing that remained to be checked were the feeders that passed through the aerial trunking between the radio room (on the boat deck), through the Captain’s cabin one deck above (located behind the Bridge ) and up to the aerial insulators on the monkey island, (two decks up from the Radio Room).
The steel trunking in the Captain’s cabin ran the full height of his cabin from the deck (floor) to the ceiling bulkhead. I cannot now be precise as to the dimensions of the trunking but from memory I would say that it was approximately four feet (one point two Metres) wide by three feet (one Metre) deep. A steel plate covered the rectangular cut-out on the face of the trunking that gave access to its insides.
The trunking on the Monkey Island had the same width and depth as that in the Captain’s cabin but was shorter being somewhere in the region of six feet (one point eight) Metres in height.
After much scraping of paint and the application of release oil to seized bolts, the aerial trunking on the monkey island was opened up to reveal a little bit of corrosion in the form of verdigris on the feeders but nothing that would explain the transmitter problems that we had been having. The only trunking left to inspect was that in the Captain’s cabin.
Captains were then and presumably still are a unique breed. The route from navigation cadet to Master of a ship is a long and difficult one and the responsibilities they have are considerable. The ones I served under without exception had their own particular take on life and held dear their own authority. Fortunately for me as a junior, it was Harry’s responsibility as Chief R/O to approach the Captain, and seek permission for us to go into his inner sanctum, make a mess and disturb his port routine. Eventually he agreed but only on a day when he planned to be ashore for a few hours thus ensuring from his point of view that he would not be affected in any way by our investigations.
When we eventually gained access to his cabin, imagine our surprise, when standing in front of the trunking, we saw that most of the bolt holes were just that, namely holes with the few bolts that remained (I think four) in situ being secured finger tight and capable of being removed without the aid of a spanner.
On removing the remaining bolts and taking the cover plate off, what was revealed was quite unexpected. Inside the trunking between the aerial feeders and between the feeders and the side of the trunking bulkheads were a collection of suitcases and holdalls and if I remember correctly a set of golf clubs. The aerial trunking was being used as a storage cupboard!
These unexpected objects were removed and the feeders inspected. I think on Mahseer there were four feeders in total that fed through that trunking.
One or two of the feeders were loose either on the top or the bottom feed through insulator. With one feeder, the copper tubing had sheared away completely from its securing lug that connected it to the deck feed through insulator that went down to the radio room. When we worked it out, that particular feeder belonged to one leg of the main aerial.
The copper tubing of that particular feeder could not be repaired because the break was located above the lug and was now too short in length to repair. We contacted the engine room and were fortunate to be given a length of copper tubing of a similar diameter that we were able to use as a replacement.
What we surmised was that the trunking had been used as a storage cupboard by numerous captains for a very long time and that the movement of their luggage against the feeders in heavy seas had eventually caused metal fatigue leading to the break in the feeder. As well as arcing across the break when the transmitters were keyed it was also likely that the capacitive effect of the case and holdalls touching the feeders would have intermittently detuned the aerials. On completing the repair we placed the luggage and the golf clubs in a neat pile in the centre of the Captain’s day room. We also left the cover plate of the trunking propped up in front of the trunking itself. We then departed the cabin leaving it as tidy (well almost) as we had found it.
When the Captain returned on board it wasn’t long before an apprentice brought the expected summons. Harry was told by the apprentice, that the Captain was not best pleased with the way things had been left.
Harry went to see him on his own so I was not privy to the conversation between them. I can only relate what Harry told me afterwards.
The Captain was very angry at the way things had been left. Harry explained the intermittent problems that we had encountered during the voyage, the cause, which was the long term use of the trunking as a storage cupboard and the damage, which was likely to reoccur in the future if the offending items were not permanently removed. Although he became less angry, according to Harry the Captain was adamant that the luggage would stay where it was.
Harry had served as a Senior Rating in the Royal Navy during World War 2 and had joined the Merchant Service as a Radio Officer after the War ended. He was respectful of rank and authority and accepted without question, that the Captain’s word was absolute when it came to Mahseer’s radio service. He just pointed out that although repairs had been made, the ships wireless station performance would continue to be impaired if the Captain insisted on using the aerial trunking as a cupboard. He also stated there was not only the impact on everyday communications to consider but also how Mahseer’s wireless station would perform in an emergency or when undertaking any radio activity related to Safety of Life at Sea.
Harry then told me that he said to the Captain that if the offending items stayed in the trunking, that he would be obliged to record the problem and his conversation with the Captain in the ship’s wireless log which the Captain would be requested to counter-sign in due course as per normal practice. He would also report the situation in a letter before we sailed from Colombo addressed to the Chief Radio Superintendent at the Liverpool Head Office. Harry promised the Captain that he would be shown the letter before it was posted and would be provided with a copy. Harry never said what else passed between them but Harry’s stated intentions brought about a complete change of heart on the part of the Captain. He said that Harry was correct to raise his concerns and that a solution to the luggage storage problem would be for the Chief Steward to find some space for the cases and bags in the owners suite (which on that voyage was not occupied). He also thought that the golf clubs could be tucked away somewhere in his day cabin.
That is how matters stayed. The inspection plate was secured to the trunking with all of its bolts (the missing bolts were found at the bottom of the trunking) and for the remainder of that voyage and my subsequent voyages on Mahseer the transmitters continued to talk to us in a very predictable manner.
Harry’s handling of the issue and his calm approach made a deep and lasting impression on me and acted as a useful template for me to follow during my remaining time at sea and during my later (non Merchant Navy) career. It also made me realise that researches or investigations of any kind can lead to outcomes that can never be anticipated at the commencement of the work.
copyright © John Leary