Thursday, 31 March 2016

LOW FREEBOARD - HMS CAPTAIN.


The West Australian, Monday 21 March 1910.
SHIPS LOST, STOLEN, STRAYED. - -
THE ROMANCE OF THE HIGH SEAS.
- (By "Sancho Pania.")

His steamer was leaving Fremantle next
day and I had accepted the cordial invitation 
of Captain X. to spend the evening with him.

.....
"Why, during my forty years' experience
at sea," continued the skipper, "there have
been scores of cases of vessels of one kind
or another setting out on a voyage and
mysteriously vanishing. It's usually only
when a passenger ship fails to reach her
destination that public interest is aroused;
where 'wind-jammers' or cargo-steamers are
concerned people hear little and care less.

Such a revealing and true statement.

Curiously enough I started to serve my
time in 1870,the very year in which the
Inman liner, City of Boston, left New York
for Liverpool with 220 passengers and a big
crew aboard and disappeared without leaving 
the smallest clue to indicate her fate."

Wikipedia:
Displacement:2,278 long tons (2,315 t)
Length:305 ft (93 m)
Beam:39 ft (12 m)
Propulsion:
  • 2 × steam engines (600 hp total)
  • single screw
Sail plan:Three-masted (ship rigged)
Speed:12 kn (22 km/h; 14 mph)

The City of Boston sailed from Halifax, Nova Scotia for Liverpool on 28 January 1870 commanded by Captain Halcrow. She had 191 people on board: 55 cabin passengers, 52 steerage passengers and a crew of 84. A number of the passengers were prominent businessmen and military officers from Halifax. She never reached her destination and no trace of her was ever found.
A violent gale and snowstorm took place two days after her departure which may have contributed to her loss. Collision with an iceberg was another explanation suggested at the time.[2]
City of Boston had been fitted with a two-blade propeller to replace her original three-blade propeller which had been broken during her previous voyage, and Captain Brooks of the SS City of Brooklyn expressed the opinion that the new propeller would not be strong enough to let her make headway against the adverse weather.



'Yes, and That was the same year H.M.S.
Captain turned turtle off Cape Finisterre and 
carried hundreds of lives to the bottom
with her," I observed.


Displacement:
  • As designed: 6,960 long tons (7,070 t)
  • As built: 7,767 long tons (7,892 t)
Length:320 ft (97.54 m) pp
Beam:53 ft 3 in (16.23 m)
Draught:24 ft 10 in (7.57 m)
Propulsion:
Sail plan:Ship rig: 37,990 sq ft (3,529 m2) of sail (max)
Speed:15.25 kn (28.24 km/h; 17.55 mph) (steam power)
Complement:500 crewmen and officers
Armament:
Armour:
  • Belt: 4–8 in (100–200 mm)
  • Turrets: 9–10 in (230–250 mm)
  • 7 in (180 mm)

The design called for the ship to have a low freeboard, and Coles' figures estimated it at 8 feet (2.4 m). Both the Controller Vice-Admiral Sir Robert Spencer Robinson and the Chief Constructor Edward James Reed raised serious concerns. Robinson noted that the low freeboard could cause flooding issues on the gun deck, and Reed criticised the design in 1866 both for being too heavy and for having too high a centre of gravity. On the latter, Reed noted that it would cause issues "especially as it is proposed to spread a large surface of canvas upon the Captain".[10] As the design neared completion, the First Lord of the Admiralty, Sir John Pakington, wrote on 23 July 1866 to Coles approving the building of the ship, but noting that responsibility for failure would lie on Coles' and the builders' lap.[

On the afternoon of 6 September 1870 Captain was cruising with the Channel Squadron of 11 ships off Cape Finisterre. The ship made 9.5 knots under sail in a force six wind, which was increasing through the day. The commander in chief was on board to see her performance, and speed had risen to 11–13 knots before he departed. Not being accustomed to ships with such low freeboard, he was disturbed to note that at this speed with the strengthening sea, waves washed over the weather deck. The weather worsened with rain as the night progressed, and the number of sails was reduced. The wind was blowing from the port bow so that sails had to be angled to the wind, speed was much reduced, and there was considerable force pushing the ship sideways. As the wind rose to a gale, sail was reduced to only the fore staysail and fore and main topsails

Shortly after midnight when a new watch came on duty, the ship was heeling over eighteen degrees and was felt to lurch to starboard twice. Orders were given to drop the fore topsail and release sheets (ropes) holding both topsails angled into the wind.[18] Before the captain's order could be carried out, the roll increased, and she capsized and sank with the loss of around 480 lives, including Coles. The First Lord of the AdmiraltyHugh Childers, and Under-Secretary of State for WarThomas Baring, both lost sons in the disaster. Only 18 of the crew survived by making it to a boat which had broken free.

This account harks back to my concerns about the Waratah having a registered freeboard of 8.1 ft.
which in the case of the HMS Captain, combined with a high centre of gravity (i.e. top heavy), had
disastrous results. In fact some sources believe the Captain only had a freeboard of 6 ft. 6 in. when
she capsized. This adjustment pointed glaringly to the fact that her centre of gravity had to be lowered
in order to improve GM stability - at the cost of seas overwhelming over her main deck. By the time
Waratah departed Durban her centre of gravity had been sufficiently lowered but she only had a
freeboard of some 9 ft. - 2.6 ft. short of the estimated safety margin.

The Captain was also a larger ship than 'contemplated by the original design specifications and rules' and her beam of 53 ft. was too narrow for a vessel of this kind. This brings us back to the Waratah and her own classification, 100 A1 spar-deck class with freeboard, and the fact that she was larger than that contemplated by those rules. Breaking the rules beckoned disaster.

Given the Captain's high centre of gravity it is more than alarming that her draught was only 24 ft. 10 in.. No allowance was made for creating suitable counter-acting dead weight / ballast low down in her hull, as was the case with Waratah. The low draught probably facilitated speed (15.25 knots) but not stability. 

No wonder she rolled over...

The HMS Captain deployed sails, unlike Waratah, which contributed to a low GM, but there are some disturbing similarities which we cannot fail to ignore !









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