The Board of Trade (BOT) rules were the English rules that drove ship design. Engineers, then and now, tend to be requirements driven. The customer has requirements and there are standards to be met (e.g. the BOT rules of back then or building codes of today).
BOT rules on sub-dividing a ship with bulkheads were loose but did specify things like how high they should go. Ship builders and owners were free to exceed the requirements (and generally did).
The BOT rules were specifically designed to encourage bulkheading. The idea was to push for unsinkable ships rather than for life saving if a ship sank. To that end, one could receive a waiver on life saving equipment in exchange for better bulkheading in the ship's design.
Because of the design of the Olympic class ships, White Star line (WSL) had the option of reducing the lifeboat capacity, under BOT rules, from the 1178 it had, to 756! WSL chose not to exercise that option and H&W erred in favor of safety by installing the Wellin davit system for greater (potential) lifeboat capacity.
With respect to longitudinal bulkheads (lengthwise watertight bulkheads), these tended to be a military requirement and were incorporated in the Mauritania class ships. The problem becomes maintaining the extra watertight accesses, particularly with problems of coal dust and the like. Olympic class ships had 15 watertight openings, Mauritania, and her sister Lusitania had 69. Historically, these caused more problems than they solved.
When the iceberg was sighted, 1st Officer Murdoch ordered a turn to port and the engines to full reverse. The controversy surrounding the engine reversal order centers on whether reversing the engines would cause cavitations and swirls of water that would reduce the effectiveness of the rudder. While the rudder seems to have started turning almost as he spoke, the activities down in the engine room suggest that if the engines were reversed, it didn't happen before the collision.
The watch engineers were not standing on the control platform, hands on the handles, waiting for an order the way they were on the sea trials. Once at sea, the engines are brought to full speed, the turbine is engaged, and the pressure dials are monitored until the destination port is in sight. A sudden and unexpected change in engine power in mid ocean might require 10-15 seconds for the nearby watch engineer to react. Stopping the engines takes the throw of a lever and can be accomplished in about 10 seconds. Reversing the engine takes the throw of two levers and about another 10 seconds. The turbine engine also needs to have its steam redirected to the condensers. The turbine engine ran on the exhaust steam of the reciprocating engines and would continue to run forward no matter what the main engines were doing. When the engines change power, signals are echoed in the boiler rooms indicating that boilers should be adjusted to produce more or less steam, based on the order. It's generally accepted that there was less than 40 seconds between the iceberg sighting and the collision.
Testimony from several of the boiler room crew that survived indicated that stop was signaled AFTER the collision, or as it was occurring. Their testimony is all we have as all of the ship's engineers and the Harland & Wolff guarantee group assisting them went down with the ship.
The issue of reversed engines becomes moot if the engines never reached reverse until the collision or slightly after. The ship turned on the rudder alone and actually turned rather well. As the ship started to collide, Murdoch had the rudder thrown to starboard and swung the stern out and away from the berg. That Murdoch was successful in this in the short distance helped prevent the iceberg damage from continuing further down the side and indicated good response from the rudder.
Given more space, the order to reverse engines can be argued to be wrong. Combinations like reversing one engine while leaving the turbine engaged to increase rudder effectiveness could well improve turning response. These sorts of maneuvers were never practiced. Mr. Murdoch was on the sea trials and all they practiced were high speed turns and emergency stops that included reversing the engines. In an emergency, people will only do what they've been trained to do and have practiced.
Following the disaster, finding from the British Inquiry was that Titanic was under-ruddered. The are politics involved with this finding. If the ship's rudder was too small, that's one less fault for White Star. If people want to believe that, it doesn't hurt H&W either because they build ocean liners, not highly maneuverable racing boats.
Why didn't Titanic (or Olympic or other big ships of the time) have enough lifeboats for all aboard? It goes back to the BOT rules for shipbuilding. The technology was advancing MUCH faster than bureaucratic rules could keep up.
Life boat numbers were based on the tonnage of the ship. If you built an 8,000 ton ship, then you needed X number of lifeboats. The scale went up to ships of 10,000 tons. Such ships needed 16 boats under davit (ready to launch). Titanic was a 46,000 ton ship, or more than four times the maximum size listed in the BOT tables. H&W installed the Wellin davit system that allowed up to four boats to be launched from each of the 16 boat positions. While only one boat was mounted at each davit position, four additional boats were mounted on the forward structure, thus Olympic and Titanic exceeded the BOT requirements.
If Titanic had another 16 or 32, probably little would have been different. Only 18 of the 20 boats were properly launched before the ship began the final plunge. Addition boats may have hindered the loading of the boats that were launched. The only crew trained in launching the boats were the seamen (44 of them) and the officers. Two seamen were put off in the early boats to provide expertise in handing the boats. This was cut to one seaman per boat because they were fast running out of seamen to man the davits.
In the technical notes of Tom Andrews, the man in charge of Titanic's construction, he calculated the ship's personnel and lifeboat capacities in precise detail. The figures, written in his hand during the early construction show several things.
The new BOT rules were not enacted. White Star elected for the Olympic arrangement of boats on Titanic. Small boat makers were swamped with orders for additional boats from all lines after the Titanic disaster.
Counter-flooding is flooding a compartment if a compartment on the other side of the ship takes on water to keep the ship level. For Titanic, this involves flooding stern compartments as the bow compartments take on water. From the testimony at the enquiry, it's clear that the idea to counter-flood to avoid a severe list was only a theory then. The Lusitania had longitudinal bulkheads, but there is no evidence that any counter-flooding equipment was built in, or that anybody on board had any idea how to counter-flood if the need arose. To that time, it had never been tried.
If counter flooding equipment were available on Titanic, then counter flooding the stern compartments to raise the bow would not have worked. Rather, flooding the stern compartments would have served to lower the stern and increase the stress on the center sections. This would also hasten flooding the ship to the point where the design is compromised and the ship would capsize.
Counter flooding is NOT a good idea.
Double hulls are also NOT a great idea! They may help in a minor collision, but in a major collision, they'll bend and break along with the outer skin. They take up a lot of space and make it impossible to do maintenance against corrosion in potentially critical areas. In short, an older ship with a double hull is probably less safe than a ship with a single hull. At least with double bottoms, you can enter and work easily standing up (Edward Wilding's thoughts). Refitting Olympic with double hull sides cost 25% of the original building cost for the entire ship!
This was a conjecture at the 1912 hearings and it has persisted as a question today. Would not Titanic have settled evenly over it's great length for a longer period of time, thus increasing the chances of help arriving in time?
NO! Ships don't sink that way. If the flooding started on the forward starboard side, then the water entering there will upset the 'trim' of the ship slightly in that direction. As more water pours in, it pools at the low spot, the forward starboard area, increasing the tip at the nose and the list to starboard. It's not like flooding a gymnasium supported by the ground.
As the water works it way back, it flow to the low sides, increasing the forward tip and the list, until launching lifeboats on the high side is impossible. As the water flows through the boiler rooms, power for the generators is lost.
Titanic had a number of bulkheads that did not have doors between the lower spaces. In fact, half of the bulkheads (mostly from the engine room aft) went up to D-deck and had only one door in the engineering spaces. This facilitated separating the classes by placing them in separate compartments with no physical access in the decks below D-deck. It also reduced maintenance and construction costs, particularly if routine access between compartments served no purpose.
If all watertight doors had been left open, the simulation model showed that the lights would be lost sometime between 12:40 or 12:50 (more than an hour earlier than actual), but the ship would still sink after capsizing some 30 minutes sooner than the actual. In short, you have a severe list that would hamper the launch of the boats and darkness for 45 minutes before the end.
Note that this scenario requires the crew to get the doors open in flooded areas, and also requires that they disable the float switches to the water tight doors. They also have to sit and watch as critical areas of the ship flood.
Note also, that when a ship capsizes, all the water in the ship has to shift to a new location, and this will happen VERY VIOLENTLY.
A primary reference here is "The Sinking of SS Titanic - Investigated by Modern Techniques" by C. Hackett, a senior naval architect at Harland & Wolff, and J.G. Bedford, a retired chief naval architect at H&W. Their paper was published for the Royal Institute of Naval Architects (RINA) in 1996. Other sources are listed that supplement their analysis.
Edward Wilding was asked about the possible result of hitting the berg head on. His figures were considered valid by the authors. In a head-on collision, the bow would have compacted some 80-100 feet, flooding the first two compartments. If three compartments were breached, you still have a ship afloat. For Mr. Murdoch, charged with making a decision, a head-on collision means you condemn the crewmen in the forward crew spaces and possibly some third class passengers in the forward spaces. The shock of the collision would have been similar to stopping your car from 25 mph by driving into barrels of water.
On the other hand, such a collision does send shock waves through the length of the ship and this can pop rivets and even steam line fittings in the center of the ship. The hull will bend and compress in a sudden stop and produce a great deal of unexpected damage. This has been found to be the case in ships suffering near misses by bombs and shells during war. The shock to the hull from a near miss can play havoc in the engine spaces.
Without KNOWING the outcome in advance, no court on the planet would have exonerated Murdoch for the loss of life without trying to avoid the collision. The testimony in court would have been entertaining reading today:
Lord Mersey: Mr. Murdoch, you saw this large iceberg before you and you made no attempt whatever to avoid it?
Murdoch: Yes, that is correct, sir.
Lord Mersey: In view of the 275 passengers and crew killed or maimed, why in bloody blazes not?
Murdoch: I figured if I tried to miss it, I might graze the berg, causing fatal damage down the ship's side that would have resulted in the ships loss.
Lord Mersey: But you didn't know that might happen. You may have suffered no damage at all. You knew steaming the ship straight at the berg would cause injury and severe damage. Is that not also correct?
Murdoch: But Sir, the ship survived. Perhaps it wouldn't have if I had turned. 6 months in dry dock and she'll be right as rain.
Particularly in the days before the wreck was discovered,
there was great speculation on the possibility of raising the ship and how
one would go about it. After the discovery, the stern section was found
to be too badly damage to contemplate such a thing so people talked about
the bow section. Could that be raised? Overall, the answer
1. There are international treaties to prevent that.
2. If you get around that detail, the cost of engineering a solution, designing and testing new equipment for heavy duty work at that depth, and lifting 25,000 tons of ship would be astronomical. The bow section is not in good shape. 20% of the side plate is not attached to the double bottom and the keel is broken in at least two places. I liken the problem to raising a train of 400 flatcars, each car carrying a 50 ton battle tank, and keeping the whole train level for the 2.5 mile lift, and not breaking the train.
That's the easy part.
3. Once the ship hit's the air, it will begin to rust to pieces in a matter of days because the steel itself is impregnated with ocean salt. Every surface in every nook and cranny must go though a detailed conservation process to leach out the salt and then be treated with preservatives. All of the wood you'd most like to preserve must be ripped out. That process would be tremendously expensive. It would require the ship be transported fully submerged to a special built facility and would take years to complete. Failure to do so would result in a very expensive rust pile as your reward.
Because of Titanic, the old BOT rules were revised at the first international conference for the Safety of Life at Sea (SOLAS) just before WW I. Because of the war, the results weren't formally implemented until 1933 (21 years after the tragedy), although builders and owners followed the new rules before then. SOLAS included standards for compartmenting and bulkhead heights. Additional standards and criteria for heel and stability after collision were implemented in 1952. SOLAS was further updated in 1965 and 1980 under the new UN name of International Maritime Organization (IMO). The International Ice Patrol, radio regulations, and other actions were implemented as well as a result of the disaster.
Of interest to us, a detailed analysis of Titanic's design against two and three compartment breach situations showed, in the author's words (para 9.4): "The studies we have made showed that the design of Olympic and Titanic is configured to comply with today's regulations with only a few exceptions involving the most recent damage stability requirements which says much for the care taken at the time they were planned." -- Bedford/Hacket paper
Further, in view that White Star and Harland &Wolff overbuilt Titanic for the rules of the period, the authors make the point, "This cannot be said of the majority of passenger vessels today where the minimum requirements are treated as the maximum with very little margin to spare."
Have a nice cruise :-)
Here's a "what if" for you! What if it wasn't the maiden voyage? What if Tom Andrews wasn't there to know the ship would sink in about two hours and tell Capt. Smith, or his successor? Because the ship changed position so slowly in the early going, would the captain have delayed starting the launching of the boats, resulting in panic and greater loss of life? Do modern captains really know the design of their ships? How bad is a bad situation? The next great disaster lies in the margins.