Blog 151 - TITANIC - PART X I - “COLLISION” AND THE FATEFUL NIGHT
- ranganathanblog
- Jan 18
- 10 min read
COLLISION
1135 pm - Iceberg spotted, the bell was rung and the lookouts immediately communicated with the Bridge. The method of communication? (Those were the walkie-talkie-less days). Probably a voice pipe or a 2-way sound powered telephone where you turn the handle and the buzzer sounds at the other end, the receiver is picked up and held to the ear.
1140 pm - Collision. The vessel collides on the starboard side with the iceberg.
First Officer Murdoch was on the Bridge at that time.
The Lookout’s message of “Iceberg right ahead” was conveyed to him.
His immediate reaction was an order to the helmsman “Hard Starboard”.
While it is debated why the ‘hard starboard’ was given, the practice of those times was continuing the Tiller Method of giving helm orders.
With a Tiller, a movement of the wheel to starboard meant the rudder turned to port and the vessel’s bow turned to port.
(With present day steering, a movement of the wheel to starboard meant the vessel’s bow turned to starboard).
The ‘Titanic’ had a steering system much like those of modern day ships and very similar to the ships of the 1950s and 1960s.
With a ‘Hard Starboard’ order, the helmsman would have turned the wheel to Port and the bow moved to port.
Murdoch also gave the order to stop engines and gave an astern order on the telegraph.
Diesel Engines of today take a while - quite a few minutes - for the rpm to come down to a safe level for an astern movement to be given, because of the momentum.
The Triple Expansion Engine’s reversal is pretty quick. Denying the engine of steam brings the rpm down quickly, but still takes a little while because of the momentum of the various moving parts of the engine and the momentum built up by the propeller.
Changing the direction of steam to the Slide Valves, changes the direction of rotation of the shaft.
But one of the disadvantages of an astern movement is that the vessel loses her steering to a very great extent.
(If you are on the Bridge during manouvers and an astern movement is to be given, you will find that the rudder order of ‘midships’ is given to the helmsman, either before the astern movement or closely follows the astern movement, as the rudder does not play any part in an ‘astern’ movement).
So Murdoch’s trigger movement to get the bow to port gets somewhat negated by the ‘stop engines’ followed by ‘astern’ movement.
The chances are that the vessel’s bow would have moved faster to ‘port’ had he not given the’stop’ and ‘astern’ order. The momentum of the vessel was just that much slower because of the ‘astern’ order.
With an ‘astern’ movement and two right handed (outboard) propellers, the tendency of the vessel is for the bow to move to starboard.
With an ‘astern’ order, the centre shaft, Parsons Turbine operated, has to be stopped, as it runs on the exhaust steam provided by the LP Cylinders of the two Triple Expansion steam engines, which exhaust steam is no longer available.
The Impact
The Titanic heavily scraped and brushed against the underwater side of the iceberg, rather than collided with the iceberg.
She was at an approximate speed of 21.5 knots = 36.3 feet per second.
By all accounts, the impact and damage was for a length of 300 feet of the hull.
300 / 36.3 = 8.3 seconds. Approximately 10 seconds of impact period, before she separated from the iceberg.
Could just 10 seconds of impact cause a vessel to go down?
2h 40 minutes to fully submerge
6 of the 15 watertight compartments flooded
She took a starboard list and was down by head quite a bit.
At one stage, just before she sank, her forepart was almost 45 degrees in the water.
The ship could not stand the strain and she parted somewhere aft of midships.
For a little while, even though parted, the two halves held together by the sheer strength of the double bottoms.
At 12 minutes past 2 am, the bow - 16,000 tons of it - parted and started going down.
By 0220 she was completely submerged and sank fast.
It took 2 hours and 40 minutes for both sections to disappear.
One of the First Class passengers to survive was 17 year old Jack Thayer who jumped into the water and clung on to the upturned collapsible, till rescued by a lifeboat. His drawing of what he remembers:
The Sinking
The Forepeak Tank was taking in water at an alarming rate, judging from the vast amount of air venting / hissing out of the Forepeak Vent Pipe. This hissing sound was heard by one of the crew. The Forepeak tank is not a Double Bottom tank and she was definitely taking in water. The rupture could have been on the keel or on starboard side of the hull or both.
One of the Junior Mates, sent forward by the Captain, said that he could hear water rushing in to # 1 Cargo Hold and also found the stretched tarpaulin ballooning, indicating air being pushed from below.
A Representation of Water flooding the Forepeak Tank and # 1 Cargo Hold
The next area that reported in was the # 6 Boiler Room and one Coal Bunker. The Firemen had to shut down the boiler and evacuate the area. The intervening Water Tight Door had already been closed, but was opened for a brief period manually, locally, for the escape of personnel. It was once again opened for the entry of people with wooden boards to try and thwart the breach, but in vain.
A Representation of the Boiler Room # 6 flooding and all working personnel in that area had to evacuate.
The Mail Room was the next to report in - they could see water below them. They had to evacuate.
Mail Room (white rectangle) personnel saw the water entering below them
Cargo Holds # 1, 2 and 3 were also flooding.
Boiler Room # 5 reported in, taking on water.
The white lines show where the Titanic had been holed (gashed), as per scans done a 100 years or so later.
From the forward side (right of picture)
Forepeak tank gash
6 feet gash # 1 cargo Hold
16 feet gash between # 1 and #2 cargo Hold
33 feet gash between # 2 and # 3 cargo hold
45 feet gash between Boiler Room 6, extending a little into Boiler Room 5
(These are from some of the reports that reached the Bridge staff).
Artists’s representation of the Bilge Keel and the rupture of steel plates - Probably, if the Bilge Keel had been broader, protruding more from the hull, it, likely would have taken up the impact, instead of the hull and rivets.
Later underwater scans revealed that the gash was not continuous, but intermittent
The rupture of the steel plates as shown by the artist’s sketch above, is definitely unlikely. Such an open gash for a 300 foot length would have sunk the vessel in minutes and would have given no chance to anybody to effect an ‘abandon ship’ scenario and lower lifeboats.
Edward Walding, one of the Chief Designers
Looking at the whole scenario from a Marine Engineer’s viewpoint, I glean the following
Her length was 883 feet.
Her draft was (approximately) 34 feet 7 ins forward.
Since the design was that the height of the Transverse Bulkhead was 10 feet aove waterline, I presume that the height of the bulkhead from keel was about 45 feet.
With her draft at 35 feet, at least 35 feet of water would have entered the Forepeak, # 1 Watertight Compartment and # 2 Watertight Compartment.
The breach of the Forward Double Bottoms is yet unknown, but can be suspected, speculated.
Vessel starts going down by head.
Taking the length of ship and the height of water in the compartments and doing a simple simulation, it is found that just a 12 to 15 degree tilt forward (trim by head) is enough to start the water overflowing from one watertight compartment to the next.
She was doomed.
A massive hole, presumably at # 5 Bunker and # 6 Boiler Room
A Riveted Plate (a representation)
Rivet giving way and water spraying in (a representation)
Possibly, a thousand (or more) rivets had given way
The crew of the Titanic, instead of sending up red flares -signalling ‘am in trouble’ - sent up white flares. In the confusion, were they unable to find the red flares?
The closest ship, the Californian, saw the flares and tried to reach the Titanic by Morse light signals. (Aldis Lamp). Since there was no reply, they just went to bed, not knowing the ship had already sunk.
There was another ship ‘Samson’ close by. They were sailing with illegally hunted seal meat. Although they also saw the flares, they did not want to get involved with the Coast Guard, so they did not go to help. Moreover, they had no Marconi sets on board. They came to know of the sinking of the Titanic almost a month later, when they reached Iceland.
The fact that one of the Titanic’s starboard side coal bunkers had been on fire for nearly 3 weeks, (possibly # 6 bunker) was hushed up by the Owners. The hull plate in this vicinity would have been considerably weakened due to the fire.
Note the blemish free portion of the hull where the coal bunker fire was situated.
If the iceberg had struck this weakened plate, it would have been disastrous. Did any of the jagged edges of the iceberg pierce this section of the weakened plate? May be, maybe.
An underwater research team in a deep diving vehicle, headed by Dr. Ballard - the original sighter of the wreckage - found a 45 foot gash in way of Boiler Room # 6 and a smaller portion continuing into # 5 Boiler Room. The weakened section of the # 6 coal bunker was adjacent to # 6 Boiler Room.
A section of the holed hull, photographed by Dr. Ballard
The gash is 45 feet long, 1 ½ ft wide, between Boiler Rooms 5 and 6
Even in today’ ship building world, the Titanic’s design is adopted in various areas.
The ‘Belfast Bottom’ for one. Today’s flat keels almost resemble the Titanic’s.
The steel frame and web spacings of the supports and interiors, the concept of transverse bulkheads- to give longitudinal and transverse strength to the vessel - dates back to the Titanic’s era.
The web and frame spacings’ distances that are followed today - differs according to the length and size of the ship - have their genesis from that era.
The steering telemotor of the Titanic now lies, nearly in fine fettle, on the wreck of the Bridge of the Titanic, after a hundred years. Titanic was one of the few dozen vessels of that era to have a ‘hydraulic’ Telemotor, with feedback. Ships of 1960s and 1970s had more or less a similar system, till electronics, computer controlled systems took over.
The Bridge and the Bronze Telemotor. The Bridge, mostly of wood, did not survive.
The memorial plaques in the foreground were left behind by various expeditions.
It is a pity that the flowing lines of the bow and the stern have given way to today’s monstrosities.
The Main Engines were (nearly) a hybrid variety, where 2 Triple Expansion Engines drove the two outer propellers and a single Parsons Turbine, driven by the exhaust steam of the TE Engines, drove the centre propeller. By design, it improved the overall plant efficiency percentage.
(I, personally, feel that the use of the waste steam from the LP cylinders to run a low pressure turbine was a touch of genius. It resembles today’s Diesel Engine Turbochargers being run on the kinetic energy of the exhaust gases AND followed by the use of the heat of the same exhaust gases to heat water in the Exhaust Gas Economiser, which fulfils all the steam needs of a vessel at sea. It is a stroke of genius).
One could cite the supposedly Water Tight transverse Bulkheads as a design flaw, as it rose to about 10 feet above waterline and not all the way through upto the Uppermost Continuous Deck, as is the case today. A simulation will reveal that the vessel needed to be ‘down by head’ by just a 12 to 15 degree angle for the flood waters to overflow the transverse bulkhead.
But even the thinking behind the construction of transverse bulkheads to cordon off the length of the ship into water tight compartments was innovative and daring. Yes, they did err in not thinking of a fully watertight compartment, but they laid the foundation for future vessels’ design.
One could cite the steel used as a flaw but, in truth, it was the best steel available in that era. Probably, the one weakened aarea of the hull would have been # 6 Coal Bunker Space, as a coal fire had been simmering for several days, which would have made the steel of the hull plate very brittle. It is to be noted that the 3D scans of later decades showed the maximum hull gash of 40 odd feet length in the vicinity of the very same # 6 coal bunker.
One could cite the wrought iron rivets - used mostly in the curved section of the hull forward and aft - as a flaw. One could also cite the excessive slag in the wrought iron rivets.
But not much consideration has been given to the scraping impact of the iceberg on the rivets.
The vessel was travelling at 21.5 knots = 36.3 feet / sec.
With the mass of 52,000 tons travelling at 36.3 feet / sec, when the rivets of the plates impact with the iceberg, what would happen?
It is akin to a metal disc grinder chopping off the bolt heads. The shank of the rivet falls inside the ship and water starts pouring in through the thousands of holes. I dare ask - can even the best welded steels of today be able to stand such an impact?
A Hydraulics expert will be able to quantify the amount of water that will enter through a hole 1.5 ins in diameter, with a head pressure of 25 feet (approximate depth from waterline that the impact took place). Multiply that a thousand fold and more.
(Taking 1.5" in shank dia of rivet, 1.5" thick plate, 25 feet head of water)
My approximate calculations = 570 litres / minute
From a thousand rivet holes = 570 tons / minute
(Somebody please correct me if I am wrong in my calculations)
Subsequently, the lack of rivets, opens the butts of the plates to the sea, increasing the rate of water ingress..
Apart from that, some plates tear because pointed icicles pierce the plating, once again due to the immensity of the impact.
How much of damage was sustained by the Double Bottoms is a mystery, as the DBs are buried in mud and are inaccessible to the 3D scans done in 2022. But there was every likelihood of the vessel having ‘grounded’ on the ice and ruptured. It could also have taken in a lot of water and added to the woes of the vessel going down by head.
So, design flaws? One - the abbreviated supposedly Watertight Transverse Bulkhead that stopped 10 feet above the waterline, which also played a huge part in the sinking of the Titanic.
Credits:
OceanLiner Designs
Britinnica
“What really Sank the Titanic” authored by Hooper McCarty, Jennifer Foecke
AR
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