Blog 155 - TITANIC - PART XV - SUMMARY - THEORIES OF HOWS, WHYS AND OTHER SCENARIOS
- ranganathanblog
- Mar 14
- 7 min read
If the orders given by First Officer Murdoch - on getting information about ‘an iceberg right ahead’ - been different, would it have made a difference?
Possibly.
21.5 knots = 36.3 feet / sec
The estimated length of impact is about 300 feet length of the starboard side of the vessel.
300 / 36.3 = 8.26 seconds of impact / scraping.
The order issued by First Officer Murdoch, on getting to know that they were heading for the iceberg was
“Hard Starboard”
“Stop Engines and Full Astern on the Engines” or words to that effect.
By giving a ‘Hard Starboard’ movement, he was giving a ‘Tiller’ movement which, on the Titanic, meant that the steering wheel is to be moved to port, to swing the bow to port.
This was in accordance to the helm orders of that time.
A ship's tiller is a lever that's attached to a rudder post or stock, and is used to steer the ship. The tiller provides leverage to turn the rudder, which controls the ship's navigational direction.
The simplest way to describe it is to see the above image of a boat’s tiller. By pushing the tiller handlebar to starboard side, the rudder moves to the port side and the bow of the ship or boat moves to the port side.
To prevent the strain of manually holding on to the tiller, they used tackles to keep it in place.
So, as per the custom of that period, the order was given as ‘Hard Starboard’, whereas the steering wheel was rotated to portside.
The custom of ‘tiller orders’ continued till 1930, after which they were ‘rudder orders’, to turn the rudder in the direction that the ship was to turn.
Even today, Masters or Pilots giving orders to the helmsman will give the order, say, ‘Port 10’ or ‘Hard- a-port’ and follow it up by raising his left arm and vice versa.
So, the steering order of ‘Hard Starboard’ was correct as per the standard of the time and the helmsman was correct in turning the wheel hardover to portside.
In my opinion - and this is argumentative - the First Officer Murdoch erred in stopping engines and giving a ‘Full Astern’ order.
Had the engines been running full speed, ahead, the thrust on the rudder would have been more. The ship would have turned faster.
Possibly scraped the iceberg and impacted for a far smaller length - or may have just missed by inches.
With a propeller turning astern, the rudder becomes ineffective to a very large degree.
On the Titanic, the configuration of the three propellers were
The Centre propeller was left handed and not capable of going astern, since it was turbine (direct) driven.
The Starboard and Port propellers were right handed, the Triple expansion
Steam engines for these propellers capable of being reversed.
Moreover, the rudder is on the centreline. The port and starboard propellers a distance away.
In an astern movement, with right handed propellers, the bow tends to move to starboard.
I do not know enough to say if the centre (turbine) shaft continued rotating in the ‘ahead’ direction. I would assume that if the two side Triple Expansion Engines had to be stopped and then given steam to move astern, the Parsons turbine - I feel - would need to be stopped.
Having given the ‘astern’ movement, Murdoch lost his steering capability, so the wheel’s movement to port was (largely) inconsequential.
Remember, the scraping impact was a fleeting 10 seconds, not more than 15.
This opinion needs the expert advice of a Master Mariner. Again, in my opinion, if he had gone ‘astern’ on one engine and ‘ahead’ on the other, the centre shaft turbine would have continued getting steam and the rudder would have been effective.
One side propeller going in one direction and the other in another direction would, likely, have turned the ship faster and away from the iceberg.
Conjecture, but those are my thoughts.
What it cannot be:
Steel
Steel quality, even though the sulphur content and manganese content was high, supposedly making it brittle. Most ships of that period were using the same quality of steel.
What it may be:
Rivets
Wrought iron rivets used at the bow and stern. They were not hammered home by a hydraulic hammer but by a manual sledge hammer.
That the wrought iron rivets were not of top quality and of a particular standard was because of the procurement policy of the H&W Department in charge of procurement. With the number of ships being built, rivets were hard to come by. Even small forges all over Britain were contracted to supply the same. Quality suffered.
Slag was a problem.
1996 metallographic analysis of several rivets revealed, through optical microscope, that the first rivet contained large, long stringers of slag that covered over 9% of the full rivet. This is more than three times the limits set in those days.
The second rivet’s slag could be seen with the naked eye - it was that large.
The important point was that the slag ran through the shaft of the rivet like cables and, finally, bent itself to where the head of the rivet would have been, had it not sheared off.
Wrought Iron was the ‘miracle metal’ of the early 1800s in Europe. By the 1850s, it had lost its lustre due to several accidents where the metal was deemed to be at fault, as scientists and engineers began to realise that wrought iron was ‘anisotropic’, defined as ‘having a physical property which has a different value when measured in different directions. An example is wood, which is stronger along the grain than across it”.
They rightly concluded that, along the slag stringers, the wrought iron was less brittle and more strong. In fact, they were as strong as mild steel.
But across the shaft, the stringers were brittle and cracked open easily.
Not much was, then, known about the rivet’s residual stress upon being hammered home nor, indeed, of the stress on plates.
This, along with one more aspect, played the most important part in the sinking of the Titanic.
What it could be:
The Titanic’s speed at the time of impact was (approximately) 21.5 knots.
21.5 knots = 36.3 feet / sec
The impact between the iceberg and the ship was along a length (starboard side) of approximately 300 feet.
300 feet / 36.3 feet/sec = 8.26 seconds of impact / scraping
Force = Mass x Acceleration
F = m x a
Mass was 52,000 tons
Speed was 21.5 knots
Force on impact wold have been massive.
If we have disc cutter / grinder or a circular saw and use it to cut off the head of a bolt, it will slice through the bolt as if it were cheese.
The Rivets, their Shanks and the Rivet Holes
The effect of the rivets of any of the shipside plating scraping against the solid block of ice with such tremendous force and at such a high velocity, would have surely sliced off the heads of the rivets, be they steel or wrought iron, be they of good quality or bad quality.
The heat generated by the impact, even if momentary, would have expanded the rivet hole.
Once the heads of the rivets are ‘popped’, the shank of the rivet would have dropped into the ship.
Water would have come in to the ship through a thousand rivet holes at tremendous pressure.
If the plates were held together by a ‘riveted butt joint’ and the rivet head shears off, the shank gets pushed in and the plates spring apart.
If the plates were held together by a ‘double riveted lap joint’, once the rivet heads shear off, once again, the shank drops in to the ship and the plates spring apart.
Moreover, with a double riveted lap joint, if the iceberg were to scrape against the plate edges, the plate edges will curl up or get damaged, opming the entire seam for water to pour in.
What About the Double Bottoms?
The photographs and the imaging done of the wreck, once the wreck was found, could only give us a look at the starboard side to a certain extent.
Quite a bit of the forward section is buried in the mud, so the condition of the double bottoms - whether it suffered damage or not - is unknown.
The ship had a flat bottom. If the Double Bottoms were breached because it ran ‘aground’ on a protruding ice shelf below the water line, the same damage of rivets ‘popping’ and plates tearing would have been experienced by the ship.
The Fore Peak was breached. # 1 and # 2 Watertight Compartments (and more) were breached.
If the Forward Double Bottoms too were damaged, then the quantity of water in the forward end would have tipped the vessel forward and she would have been ‘down by head’ quite a bit.
The ‘Water Tight’ Bulkheads
The length of the ship = 882 feet. Draft = 34 feet
The Water Tight Bulkheads were designed to be 10 feet above waterline - empty above it.
It would have taken a tilt (forward) of only about 12 to 15 degrees (longitudinal axis) for the water inside each compartment to overflow into the next.
The ship had no chance.
Would today’s welded ships, with improved steel, have withstood such an impact?
I doubt it.
The welded seams would also have given way, cracking the plates at the weakest points.
The advantage of the fully water tight bulkheads would have been the only saving grace, if the vessel had been following proper procedures before putting out to sea.
The presence of today’s improved scantlings in the impact area would not have prevented it or lessened the impact, lessened the damage.
I mention this as several ships - in my own experience - have sailed out of port with the Under Deck Passage’ Water Tight Doors open and not dogged down, compromising the water tight integrity of the ship.
Life Jackets of that Era (From FaceBook)
Life vests, or lifejackets, played a crucial role during the Titanic disaster on April 15, 1912. These lifejackets were constructed from canvas and cork, designed to provide buoyancy in emergencies. While they offered some level of flotation, the design had significant flaws. The rigid structure could cause injuries, especially when individuals jumped into the water from great heights, leading to potential neck and head trauma. Additionally, the lifejackets' buoyancy often kept individuals' heads above water but did not protect them from hypothermia in the freezing Atlantic temperatures. Consequently, many passengers succumbed to the cold despite wearing life vests. Today, only a few of these original lifejackets exist, preserved in museums and private collections, serving as somber reminders of the tragedy.
AR
Comments