# Degaussing Equipment?



## SimonBrown (Jan 13, 2018)

In the forecastle of a second world war era merchant ship there is a cable drum, wound with what appears to be heavy cable. The drum is located just beneath a hatch.

Attached is a screenshot of the object in question. It is 1.2m overall length and 0.7m of wound cable diameter. Diameter of the cable itself is approx 76mm or 3".

We know the ship was degaussed just after launching, and presumably would have needed degaussing again at some point...if it had not been sunk before reaching its destination...

Friend and colleague Grahame Knott thinks this could be degaussing equipment, but would welcome any opinion from the forum to either confirm or suggest an alternative purpose...


----------



## borderreiver (Oct 11, 2008)

Was there any elec connections. feel from the bad picture looks more like a insurance wire.


----------



## SimonBrown (Jan 13, 2018)

borderreiver said:


> Was there any elec connections. feel from the bad picture looks more like a insurance wire.


At this stage, we don't know. Connectors could be in the silt or taken as souvenirs.


----------



## SimonBrown (Jan 13, 2018)

Here's a link to a view of the entire room:

Forecastle Room plan


----------



## borderreiver (Oct 11, 2008)

degassing These are normally a set of cables that is warped a round the ship on tankers it went on the main deck just inside the ship completely round the ship meeting in a black box in the engine room We had a book were mine fields could be were we would turn the switch on and another coil under the magnetic compass so as to keep it corrected. hardly used. before the ship sold out of flag the RN contractors come and removed it all as it was costly copper cables.


----------



## Dave Woods (Apr 9, 2006)

The only degaussing cables on ships I ever saw were down the hatch wound around the ship at about water level, and were built into the ship.


----------



## lakercapt (Jul 19, 2005)

I sailed on Palm Line ships when new and they were fitted with this degausing cable which was right round the boat. We went to a place off Portland and steamed back and forward through a marked range. This to get the ships signature before and after the current was swithed off.
When this was no longer needed I bellieve some crew memebers cut it off and sold the copper cable for a lot of money!


----------



## oceanmariner (May 23, 2016)

In the 60s I was on a US destroyer built in WWII. The degausing cables went around the ship, but built into the inside the hull. In the wheel house was a rotary switch that was turned to match the course of the ship. I assume sending current thru the cables in different directions or current levels.
I've seen the cables on merchant ships, but they were outside the hull in large conduit. Probably warships had a permanent installation and the merchant was temporary. But the cables have to be in position all the time. You don't store them on a reel. Most US Navy ports had a degausing range that ships passed thru to enter or leave the port. So navy ships were continually checked.


----------



## Michael Taylor (Aug 31, 2008)

On my first vessel as an Apprentice...the City of Madras (1958)....the degaussing cable ran inside at upper tween deck level. I remember passing over the coil off the Isle of Grain. Told what it was for but not how it worked but I suppose if you stayed inside those charted mine swept areas you were fine!


----------



## jmirvine (Nov 23, 2006)

Simon Brown - I doubt very much if it was DG cable. As others have said, DG cables on merchant ships were a permanent installation right round the ship. 
Did your friend and colleague Grahame Knott ever work offshore for BP in the forties field? I recall someone of that name when I worked there.

Oceanmariner - You say there was a rotary switch that was set to match the course of the ship. At one time I was on a RN Minesweeper which had a gadget called a "5 step course corrector" which I believe carried out the same function automatically. There was also a thing up the mast which measured the heave, pitch and roll of the ship and sent a signal to a box of tricks which adjusted the current to compensate for the magnetic effect of us bouncing around the ocean.

As to the original question, perhaps it was a cable to hook up to shore power while in dry dock. Just a guess though.


----------



## garry Norton (Jun 8, 2009)

From memory the Rosebank had degaussing gear behind a grill in the hatches which had to be cleaned behind when we loaded wheat in Geraldton,Western Australia.The Australian inspectors were very insistant on the space behind was clean.No doubt the Bank Line experts could tell me if I am right


----------



## saudisid (Mar 17, 2014)

Michael Taylor said:


> On my first vessel as an Apprentice...the City of Madras (1958)....the degaussing cable ran inside at upper tween deck level. I remember passing over the coil off the Isle of Grain. Told what it was for but not how it worked but I suppose if you stayed inside those charted mine swept areas you were fine!


Mike
When we were in the City of Montreal 72/73 if I remember right we had the de gausing working when we crossed the bar at the Pussar River going up to Chalna. Percy Redhead had you frd and both Mike Ashton and myself on the bridge. Mike taking visual bearings and me on the Radar, Position every 2 mins [ Used a wreck of a Bank Boat nothing else to use ]. When we sailed there was only me on the Bridge with him. Wonder what changed.
Alan


----------



## Michael Taylor (Aug 31, 2008)

saudisid said:


> Mike
> When we were in the City of Montreal 72/73 if I remember right we had the de gausing working when we crossed the bar at the Pussar River going up to Chalna. Percy Redhead had you frd and both Mike Ashton and myself on the bridge. Mike taking visual bearings and me on the Radar, Position every 2 mins [ Used a wreck of a Bank Boat nothing else to use ]. When we sailed there was only me on the Bridge with him. Wonder what changed.
> Alan


Yes had forgotten that. Not sure how you tell a magnetic mine from a dead water buffalo floating by.


----------



## oceanmariner (May 23, 2016)

On the destroyer, the switch only had 4 positions 90° apart, as I remember. The bridge crew was responsible to change the switch. The only time we use it was going thru the degausing range. Mid to late 1960s, no mine warfare going on.
If there was another degausing control on the mast it was busy on a destroyer. I didn't know of it. Most of the WWII weapons were gone except for the main guns. Some ships had one or more gun mounts removed for newer equipment, helo deck, etc.


----------



## Clifford Cocker (Jan 21, 2008)

*Degaussing Equipment*

The last ship I sailed on with degaussing fitted was the mv Birchbank circa 1974. I joined it on it's second voyage in the SW India Dock, London loading for Persian Gulf. We were leaving London and at that time there was a check point just below Tilbury, I was Second Engineer and on watch at that time, the telephone rang and I was asked to switch on the degaussing for a check, I hadn't a clue where the breaker was (my first voyage on the ship) so I asked "What mode?", there was a bit of a delay which gave me the opportunity to find the breaker. the phone rang again and I was told tah as we were North of the Equator that was the setting, I thanked them very much and switched it on. I was asked later on by the Old Man "why the delay" when I told him the true reason he said "you need watching!!"
Cliff Cocker


----------

