Flash, Bang but no Wallop – the story of Operation Grapple Britain’s H Bomb Tests


Christmas Island ChartOperation Grapple was the name given to the series of British Nuclear tests of the Hydrogen bomb, they were conducted between 1956 and 1958 at Malden Island (now called Kirimati) in the Central Pacific and at Christmas Island. There were nine tests, which was the start of Great Britain becoming part of the Nuclear Powers.

All of the bombs were exploded in the air, rather than on the ground, to reduce the effects of nuclear fallout, the first three bombs were dropped from Valiant aircraft and detonated at around 18,000 feet, around 30 miles south of the island.


Operation Grapple was a massive tri-service operation, the account below is from Martyn Hobbs, who was a Third Officer at the time and provides interesting reading.

The adventures of a Third Officer

I transferred from the armaments stores carrier Fort Langley to Fort Constantine in Singapore on the basis that Fort Constantine was de-storing on her way home after a year at Christmas Island as part of Task Force Grapple supporting the Nuclear Weapons test programme based on the island. Her Third officer wanted to stay out in the Far East (local girl friend), I wanted to go home to get married, both Captains were agreeable and a quick exchange of signals with Admiralty confirmed the exchange. The two well satisfied third officers duly transferred and signed on their new ships. A few days later Fort Constantine received new orders – load stores (victualling and naval) and sail – back to Christmas Island until further notice .
And so began my central Pacific experience.


Fort Constantine 3rd Officer 24 Aug 1957 to 23 May 1958

Capt Franklin G Edwards (Christmas Island Deployment)
Chief Officer Harry Carr
2nd Officer George Sheriff
3rd Officer Martyn Hobbs
Deck Apprentice Chris Brunt
Radio Officer Doug (Kyushu) Cunningham
Electrical Officer John Thomas
Doctor Wylie
Deck and Engine Room crew were Indian mostly from Bombay
Catering staff were Indian from Goa

Naval and Victualling Stores personnel were also embarked and they lived in the additional accommodation constructed in the tween deck either side of no 3 hold. This area also contained our ward room and bar.
In all about 100 souls on board.


RFA Fort Constantine

RFA Fort Constantine


Storing in Singapore took another two or three weeks which, added to the same sort of period spent de-storing, gave the officers and naval stores staff attached to the ship plenty of time to relax and form social relationships with the large ex pat community of Singapore. When we finally sailed for a ‘secret’ destination – nobody was supposed to know that we were going back to Christmas Island – we left a lot of friends and some families waving goodbye on the dockside. I wondered whether security might have been prejudiced as we moved off the quay to the strains of Bing Crosby ‘Dreaming of a White Christmas’ playing on the SRE which had been hooked up to the loud hailer!

Our passage to Christmas Island was due east as the crow flies but there were many islands between here and there. It was the most fascinating voyage I had experienced up to that time and one that I will never forget. Threading our way through narrow passages between green tropical islands beneath cotton wool skies brought sharp reality to some of the tales of Joseph Conrad that I had read in my school days. 

Fresh water was a highly valued commodity in Christmas which accounted for Fort Constantine’s double bottom tanks having been modified so that she carried considerably more fresh water but at the expense of oil fuel bunkers. It is a long haul from Singapore to Christmas so we had to call at Manus, a port in the Admiralty Islands north of New Guinea to replenish bunkers. This was where I first witnessed the skills of the old man in berthing the ship without the aid of tugs or thrusters (thrusters had not been invented anyway!) no mean feat for a single screw ship with limited power.

We stayed only long enough to get fully fuelled before setting off again for Christmas passing many more islands on the way.


Arrival at Christmas Island

We moored on ‘Charlie’ buoy in the anchorage off Cook Island which became our ’home’ for the rest of the year apart from a number of trips to other islands.

Christmas Island Chart


We soon fell into a routine of boat runs to the Port of London (Port Camp) using our NST’s (Naval Stores Tenders) supplemented by the LCM’s crewed and operated by a Royal Marines detachment based in Port Camp. Our job was to feed and support the military personnel and scientists inhabiting the port camp, main camp and airbase. At peak demand there were as many as 4000 mouths to satisfy.

The Ministry of Supply ran a weekly airfreight service from UK to Christmas bringing urgent stores and personnel. The flight called at Honolulu for it’s last fuel stop and at the same time collected our Victualling Stores Officer’s (VSO) weekly order for fresh veg!

This meant a late run for our duty Naval Stores Tender (NST) crew to take the victuallers ashore where they were responsible for distributing the fresh veg. That which was not for immediate issue was then brought back in the NST and kept in our cool stores until issued to ships and Port Camp customers. It sounds mundane stuff but the late night return trip from Port Camp to the ship was not easy. The channel was marked with rather small buoys which may have had lights on them at some time. They rarely worked as far as I recall and we had to find them by the light of an Aldis Lamp and hope that we did not run over a coral head while searching for the passage. NSTs relied on fresh water pipes on either side of the keel to circulate coolant for the twin Perkins engines. Very efficient until they got damaged by coral encounters! Our star NST driver was our apprentice Chris Brunt and it was he who usually got the fresh veg run.


Home Made Boat Chart

Boat Chart (Home Made)



Most times the weather was kind to us and the NST and boat runs to and from the Port went uneventfully. On the rare occasions that the weather turned against us it blew from the West and our berth and the trips to shore became less comfortable. Those ships moored on buoys had few worries except for the disruption to boat traffic. Ships laying at anchor needed to maintain anchor watches and be prepared to move. There were only three proper mooring buoys (Charlie, Delta and Zulu) and these were invariably occupied by Fort Constantine, HMS Messina and any visiting supply ship.

Rescue of drifting water barge.

Although there were some wells on the island, mostly brackish water, the task force ashore depended on water brought in by tankers. It was stored and transported ashore by a dumb water barge which was moved by the LCMs.

On one of the few occasions we experienced bad weather the Quartermaster on gangway watch saw that the water barge which had been moored on Delta buoy had broken it’s mooring wire and was drifting off towards Semple Reef. Chris Brunt and his crew were scrambled in one of the NSTs and he managed to get a line onto the barge before it grounded on the reef but was unable to make any headway off the lee shore. A radio call to Port Camp summoned one of the LCMs which together with our NST got the barge back to its buoy and securely moored. We received the thanks of the shore based community for saving their water supply.


Loss of cutter, crew and passenger.

There was one other occasion which had a tragic conclusion. One of our Indian crew members had received news of serious illness of a close family member and was to be repatriated on the first available flight from the island. This left fairly early in the day so the 32ft cutter with its passenger was sent away at first light in good sea conditions.

Without warning the wind increased rapidly from the west accompanied by a rising sea which must have been breaking in the boat passage by the time the cutter had reached it. The cutter failed to arrive at the boat landing. A helicopter was sent up from the airstrip and searched for the missing boat and crew. Sadly there was no sign of them. Within barely an hour the wind had dropped the sea went down and wreckage began to be found in London boat passage. Shortly afterwards I was sent out in an NST to search a large piece of wreckage that had drifted out into the anchorage. It was the upturned forward section of the cutter which had evidently broken in half just forward of the engine mounting. With boat hooks and grapnels we rolled it over so as to be sure there were no bodies trapped beneath. Nothing – it was an empty shell, even the thwarts had been ripped out by the force of the wreck. The stern half was never found.

We lost two deck crewmen, one engine room crewman and most tragic of all, the man who was going home on compassionate leave.


Ministry of Supply Cargoes

All of the non perishable bulk stores for the Task Force came out from UK in commercial ships chartered by the Ministry of Supply. Ships that I remember included the Ben Line ‘Ben Wyvis’, a Bank Line ship and Ropner’s very smart cargo liner ‘Somersby’ which later became RFA Reliant.

As the resident ‘experts’ in berthing ships in the anchorage off Cook Island Fort Constantine was called upon to look after each new arrival. Captain Edwards would be taken over to the arriving chartered cargo ship to provide a pilotage service and his ‘pilot boat’, either one of our NST’s or our 32ft cutter before it’s loss, would become the mooring boat and the coxswain and crew would turn into buoy jumpers. For this exercise the coxswain would be either Chris Brunt or the Third Officer (me!).

Buoy jumping is not a sport to be undertaken lightly! Fortunately for us jumpers Franklyn George Edwards was a highly skilled ship handler and made our job that much easier. Looking back at what we did in those days I wonder what Health and Safety would have to say about it now??

As soon as the supply ship was secured to her buoy the offloading of her cargo would commence. The main lighterage task fell to the squadron of LCM’s crewed by the Royal Marine detachment. They would move the bulk of the stores delivering either to Port Camp or to Fort Constantine. If the weather was really calm and set fair we would sometimes have the supply ship alongside Fort Constantine which remained on Charlie Buoy. This was the faster way to transfer NAAFI stores and dry provisions etc which were stored and issued from Fort Constantine.


Chummy Ships

We became very chummy with the Royal Marine LCMs mother ship HMS Messina, a somewhat battered LST of D Day vintage (Landing Ship Tank). She was virtually a permanent member of Task Force Grapple.

Another chummy was HMS Resolution (precursor to the nuclear submarine of the same name) which was a MFV, otherwise recognisable as a wooden hulled copy of a typical Scottish fishing vessel (Snibbie) commanded by Midshipman Underwood. Resolution was a few feet longer than our ten ton NST’s which were ‘commanded’ by our Apprentice Chris Brunt and yours truly on the days when I was not OOD. Apart from Messina and Resolution and occasional but rare visits from RNZN ships the RFA was the dominant fleet at Christmas Island. The one RNZN frigate I remember calling to visit was HMNZS Rotoiti (known irreverently as the ‘Rotating Tittie’). Of the RFA’s that joined the task group Wave Master and Green Ranger were regulars. We also had a visit from another Fort (possibly Duquesne or Dunvegan) commanded by Commodore Tommy Elder. During her stay alongside us a Fort Constantine raiding party boarded her and purloined their wardroom sign (a signwritten plaque advertising the ‘Commode d’Or’). It was a very nice trophy but our old man made us give it back to avoid upsetting the commodore who apparently took it with him from ship to ship.

Green Ranger’s job was to hump fresh water from Pearl Harbour to Christmas to supply the fleet and the island.


Barracuda Curry and its effects

With the ship moored for days on end many of the off duty crewmen were to be seen dangling fishing lines over the side or off the stern and using all sorts of baits and lures. The water was so clear that shoals of parrot fish and what looked like mackerel could be seen and were frequently caught. We had already been warned not to eat the parrot fish as they were toxic and didn’t taste good anyway. The mackerel-like fish did not appeal as they appeared to feed frenziedly on the overside discharge from every toilet flush!! Logically they became known as ‘shitfish’. However they proved ideal as a live bait for bigger fish.


Great Barracuda


This brings me to the tale of the big barracuda. A group of the sailors had lines out over the stern at least one of which was baited with a live mackerel doing its best to get off a large hook. The catch from this method was usually Wahoo or Grouper both of which were very good eating when fresh although they tended to loose taste after being frozen down. On this occasion amid great excitement the sailors landed a 70lb Barracuda which seriously objected to being hauled out of the water and nearly took off one of the Sailors’ legs before being despatched with a hand spike. It was a weekend and in no time the Indian Crew galley in the poop deck house was busy converting the Barracuda into a huge curry. Occasionally individual officers were invited to sample the curries from the crew galley and I can truthfully say they were always delicious – but it was best not to observe the preparation if you had anything other than a strong stomach! On this occasion we had our own Officers galley amidships preparing meals for our regular Sunday ‘curry tiffin’ so the Barracuda curry was only eaten by the deck and engine room ratings. The Officers’ cooks and stewards also fed from the midships galley.

Within hours there was a queue of very sorry looking sailors and engine room crew pleading for medicine from the ship’s doctor. It did not take long to work out that they were suffering from food poisoning and some were becoming very ill with it. We ended up with virtually the entire deck and engine room complement laid up with vomiting and diarrhoea for several days and about half a dozen of the seriously ill having to be taken ashore to be treated in the Island’s hospital facility.

Today some 50 years after the event I discovered from an article in ‘Seaways’, the journal of the Nautical Institute, that it is dangerous to eat so called ‘tropical reef fish’, particularly Great Barracuda (sphyraera barracuda), because they frequently contain the non bacterial form of poison Ciguatoxin and especially those of about 40lbs or more. On Fort Constantine we called it Barracuda’s Revenge! The article recounted the recent sad experience of a ship trading in the Caribbean which had to land 23 sick men out of their total crew of 35 after eating a barracuda caught on a fishing trip!

I don’t suppose we were the first to learn of the hazards of dining on Barracuda and evidently we were not the last.



Task Force Grapple


And this is what it looks like