Counterfactual: Sinking the Mauretania
Cunard’s Mauretania left Queenstown for New York on 14 April 1912, three days behind Titanic. For the sake of a counterfactual, this post imagines a scenario where the Cunarder struck an iceberg and sank instead.
Edward Wilding and Leonard Peskett produced a joint memo for the British Wreck Commissioner’s court to try and answer the hypothetical question about whether Mauretania would have remained afloat if she had sustained similar damage to Titanic:
We have considered by approximate methods the flooding of the Mauretania in the event of an accident similar to that met with by the Titanic. We have assumed the watertight doors and hatches to be closed and similar deductions to those made in the calculations for the Titanic. From the calculations made, taking the vessel as damaged from the stem to the afterend of the forward boiler room (corresponding nearly – but not quite – to the length from the stem to the afterend of the No. 5 boiler room in the Titanic) the vessel would remain afloat with a considerable list, say 15 deg. to 20 deg., which, no doubt, could be slowly reduced by carefully flooding some after spaces on the opposite side. With the data available we do not think we can satisfactorily discuss flooding corresponding to the damage extending into No. 4 boiler room in the Titanic.
Their memo considered a specific scenario and it is not clear Mauretania could have remained afloat. Wilding explained: ‘in order that the water should not rise above the top of the bulkhead, we had to assume the bunkers flooded on the other side. [author’s emphasis] It would be quite a practicable operation by raising the watertight doors, but they would have to be opened so that the water could get through to the port bunkers’. The longitudinal watertight bulkhead in the foremost boiler room would contain flooding, but at the cost of causing a considerable list to the starboard side. Peskett testified that he had no knowledge of any successful counter-flooding being carried out. Wilding thought it ‘a dangerous thing to do, to try and remedy such a defect by letting water into a much larger compartment than you already have it in’. He also thought that, with such a serious list, ‘water might find some other way in’ apart from the initial damage (such as through open portholes). Their analysis also excluded potential damage equivalent to what Titanic may have incurred in the way of her boiler room 4.
There does seem a narrow possibility that Mauretania could potentially have survived, but this counterfactual will assume that efforts to correct the serious list to starboard would have been unsuccessful. That would mean water would have risen above the watertight bulkhead. The Cunarder would therefore have foundered, sinking by the bow and with a serious starboard list.
Turbine driven ships such as the Cunarders needed to have both separate ahead and astern turbines. The reason for this was that the ahead turbines could not be reversed. One concern, expressed in a memo to Cunard management dated 7 February 1911, was that they only had astern turbines on two of the four propeller shafts. This caused a delay in stopping the ship:
When going full speed ahead and the order is given to go astern, the rotors on the centre shafts are going astern quite a time before the ahead rotors on the wing shafts have stopped going ahead. This will retard the progress astern and of course there will be a little drag from the wing propellers after they have stopped going ahead.
Cunard opted prior to April 1912 to include astern turbines on all of their new Aquitania‘s propeller shafts, recognising that this was a better configuration. Might they have faced criticism for Mauretania‘s manoeuvring abilities? The combination propelling machinery arrangement on Olympic and Titanic meant that the port and starboard (reciprocating) engines could be stopped and reversed, even though the turbine driven centre propeller only operated ahead. Titanic‘s stopping distance on sea trials was also far less than Lusitania‘s.
Mauretania was equipped with a total of sixteen lifeboats under the older style radial davits, also providing a capacity far short of the maximum number of passengers and crew she could carry. Their absolute and relative capacity was somewhat less than Titanic‘s. As Leonard Peskett recalled in May 1912:
When the question of boat capacity of such ships as the Mauretania and Lusitania was brought forward, the special subdivision of those particular vessels was taken into account, and it was considered that owing to the extraordinary precautions which had been taken, the total capacity of boats necessary to be carried would be fully met by the existing Rules’
Might Cunard have faced criticism that Mauretania‘s lifeboat capacity was slightly less than Titanic‘s? Or that her davits were not as advanced as the new Welin design used on Olympic and Titanic?
If Mauretania was listing significantly, it might have meant that the lifeboats on one side of the ship would have been unavailable for use. Peskett acknowledged this problem in relation to Aquitania, in September 1911:
it would…be more easy to control the passengers and get them away into boats from the gangway doors on E deck, than it have a rush of 4,000 people on to the boat deck, struggling to get into the boats, which would probably be available on one side only…
Titanic was remarkable for only taking a relatively small list to either side during the sinking process, but any significant list Mauretania took which led to many of the lifeboats being put out of use might have led to criticism of the longitudinal watertight bulkheads used in her design. Peskett noted that the Lusitania and Mauretania model of transverse watertight bulkheads (running across the ship from one side to another) and longitudinal watertight bulkheads (running parallel to the ship’s side) was the only one of its kind in the British merchant service.
Above: Mauretania‘s configuration included coal bunkers along the ship’s side, separated from the boiler rooms by a longitudinal watertight bulkhead. (Scientific American, 1912/Author’s collection)
In the summer of 1911, Cunard were working on designs for their new Aquitania. The Board of Trade’s new rules concerning stairway escape from the lower passenger decks (primarily third class accommodation) concerned Peskett because they might ‘necessitate a rearrangement of the whole of the ship above E-deck’. Cunard therefore pushed back on the grounds it would put their new ship at a competitive disadvantage:
It was pointed out…that to do so would prevent the ship becoming a commercial possibility, and that such an arrangement could not be considered by the Cunard company, as it would prevent them from competing with rivals, who with similar ships will not have to comply with such stringent regulations. The Olympic and Titanic and the new German ships will not be called upon to carry out these rules.
…It was pointed out that the Cunard Co. did more in the way of making the ship practically unsinkable, than any other company in the world, and that in the matter of [watertight] subdivision, was far in excess of our Board of Trade rules, or [Lloyds] Registration Society’s requirements, and as an extraordinary precaution, the Cunard Company are anxious to fit W.T. bulkheads between E and D decks.
Their viewpoint prior to April 1912 might have been taken as a complacency as to the safety of their express passenger ships. Might Cunard have faced criticism for pushing back against a safety regulation on competitive grounds? Might the company have been criticised for thinking their express ships were ‘practically unsinkable’?
Mauretania was expressly designed for speed and so her specifications had noted:
As the weight of all materials to be worked into the hull, fittings, and machinery is of vital importance, it is essential in getting out the designs of the various parts that the greatest care should be taken to avoid unnecessary weight, every part to be as light as possible, consistent with the necessary strength.
To keep overall weight down and help improve the ship’s stability, high-tensile steel was used in the upper hull structure rather than the usual mild steel. This was an innovative feature enabling them to use less steel to obtain the same strength.
During Aquitania‘s design process, Cunard made clear that an essential criteria of any design proposal had to be a GM (metacentric height) which was not less than Lusitania and Mauretania. This would ensure that she was not too tender. (A positive GM was essential for a ship to return to upright: if the GM was too low then she would be too tender, with less stability; a GM which was higher would produce a more stable ship.) Thomas Andrews noted in the summer of 1910 that Olympic and Titanic‘s stability:
would be so much greater than that of the Lusitania and Mauretania that lightness in the upper works was not a vital necessity with them as it had been in the case of these two ships’
Might Cunard have faced criticism that competitors such as Olympic and Titanic were superior in that regard, as Thomas Andrews had indicated? Their own criteria for Aquitania indicated that they recognised Mauretania‘s stability as an issue.
Another factor was that Mauretania‘s design used ordinary steel rivets to rivet high-tensile steel plating. Part of the reason for using high-tensile steel was to help improve stability and reduce the weight of the upper hull structure. The shipbuilders believed that the use of hydraulic riveting and the use of rivets ‘at least equal to the requirements of Lloyd’s rules for mild steel plates of equivalent strength to the high tensile steel used’ mitigated this concern’. It was a reasonable approach to take but there had been some comment about it back in 1907. Might Cunard have faced criticism for ‘inferior’ rivets?
This discussion is a mere counterfactual. All of the potential criticisms that Cunard might have faced are speculative, but they are based on known facts. They help to get us thinking about Titanic in the broader context. It is easy to see how Mauretania might have been the subject of a disaster. She actually had a long and successful career, as did Olympic: Titanic’s problem was striking the iceberg!
Much of this post is drawn from primary source documentation included in Olympic & Titanic: Triumph and Disaster, released this month.
