Read an Excerpt

Titanic or Olympic

Which Ship Sank? The Truth Behind the Conspiracy

The History Press

ISMAY'S TITANS

The Olympic-class liners – Olympic and Titanic, and later Britannic – represented a 50 per cent increase in size over the Cunard vessels Lusitania and Mauretania, which were the largest and fastest liners in the world at that time. Although the Olympic-class liners would not be as fast as the two Cunard greyhounds, White Star Line policy was to emphasise the luxury of its ships' passenger accommodations rather than speed.

To facilitate the construction of these three colossal vessels, Belfast shipbuilder Harland & Wolff would be required to make major modifications to its facilities. Two new slips were constructed in an area previously occupied by three. The William Arrol Company Ltd was contracted to construct two huge new gantries over these slips to carry the travelling cranes that would service them. When completed, the gantries covered an area 840ft long by 270ft wide.

Although the Olympic-class ships were originally conceived by J. Bruce Ismay, managing director of the White Star Line, and Lord William Pirrie, managing director of Harland & Wolff, their actual planning and design was carried out by the shipyard's principal naval architect Alexander Carlisle. Thomas Andrews was head of the yard's design department and oversaw the creation of the plans of the class prototype (Olympic) but Carlisle took charge of the details until he resigned in 1911. Throughout all stages of design and planning, all drawings and specifications were submitted to Ismay for his approval. Any modifications or suggestions he believed necessary were, without a doubt, carried out.

Of the three ships, Olympic and Titanic were built first, side by side in the two new slips, whereas Britannic would not begin building until three years later. When completed, Olympic and Titanic registered at just over 46,000 gross tons each and measured 882ft 9in long and 92ft 6in wide at their maximum breadth. As a comparison to later ships, the German Imperator of 1913 was 909ft long and the Queen Mary of 1936 was just over 1,000ft. In an age of industry and accomplishment, these new ships would be true leviathans and would secure for the White Star Line a pre-eminent position in the North Atlantic steamship trade for years to come. Having a trio of the same class would also permit the White Star Line to guarantee a weekly service in each direction.

The Olympic-class ships were driven by a triple-screw arrangement powered by three engines of two different types. The port and starboard wing propellers were driven by two giant reciprocating engines, a form of motive power that was well established and highly reliable. These engines worked in much the same fashion as an automobile engine – with giant pistons and crankshafts – save that steam pressure was used to move the pistons within the cylinders. These engines were of the four-cylinder, triple-expansion type with a high-pressure, an intermediate-pressure, and two low-pressure cylinder bores of 54in, 84in, and 97in diameter respectively; each one had a 75in stroke. They were designated 'triple expansion' because the high-pressure steam from the boilers was fed first into a high-pressure cylinder, then, after it had expanded and moved the piston in that cylinder, it was exhausted into an intermediate-pressure cylinder to expand further and move that piston, and thence into two low-pressure cylinders to expand further and move those pistons. It was an economical means of propulsion in that the steam was made to do its work three times, although this type of engine did not yield speeds as high as a newer type of engine: the marine steam turbine.

The turbine engine – the motive power used aboard the Lusitania and Mauretania – functioned by directing steam past a series of vanes, closely grouped and fitted around a shaft directly attached to the propeller. In the same way that a windmill functions, the high-pressure steam expanding and passing through the turbine forced the vanes to spin the shaft. Higher speeds were possible than could be attained with reciprocating engines, albeit at the cost of more coal. As the White Star Line's goal was luxury and not speed, this design was not favoured as the principal means of propulsion for the Olympic-class ships. However, the turbine could be used in another way. By incorporating a low-pressure turbine engine in addition to the other two, use could be made of the latent energy that still remained in the steam even after it had been exhausted at sub-atmospheric pressure from the low-pressure cylinders of the reciprocating engines and before it was condensed to water and returned to the boilers. This low-pressure turbine drove the central propeller shaft, although it could only operate at higher speeds. After trials on various ships, the combination of two reciprocating engines and a single low-pressure turbine engine was found to be the most economical in terms of coal consumption and yielded a service speed that was eminently satisfactory. Each of the reciprocating engines developed 15,000IHP (indicated horsepower) at 75RPM (revolutions per minute). The low-pressure turbine developed around 16,000SHP (shaft horsepower) at 165RPM. Combined, the three engines within each of the Olympic-class ships could generate up to 51,000HP (and just over 59,000 if forced), giving the ships a service speed of 21 to 21½ knots with up to 24 knots possible when required.

The steam required to power the three massive engines on each ship was provided by twenty-nine huge boilers arranged side by side in six boiler rooms. Each had multiple furnaces within which the coal burned to heat the feedwater into steam. The five boilers in the aftermost boiler room were single-ended, with furnaces at one end only. The remaining twenty-four were double-ended, and were twice as long, with furnaces at each end. With three furnaces in the five single-ended boilers and six in the double-ended ones (three furnaces at each end), this required up to 159 furnaces to be kept burning with coal simultaneously. All had to be fired in a never-ending rotating sequence, and every piece of coal had to be shovelled by hand. This required a 'black gang' of 175 firemen, plus more than seventy-five trimmers whose job was to move the coal from the bunkers to the boilers. With the ship running at its normal service speed of 21 to 22 knots the furnaces could consume 620 to 640 tons of coal per day. The ship's coal bunkers, situated between the boiler rooms, had a combined capacity of 6,611 tons and an additional 1,092 tons of coal could be carried in the reserve bunker hold just ahead of the forward-most boiler room.

Steam from the boilers not only powered the engines that drove each ship, it also generated electricity. Four powerful 400kW dynamos, or generators, were driven by steam and provided electricity for the ship's lighting, supplemental heating, much of the galley equipment, telephones, Marconi wireless equipment and myriad other needs. There were literally hundreds of miles of electrical cable throughout these massive ships; the lighting alone was provided by way of approximately 10,000 incandescent lamps. The four main dynamos were positioned in two side-by-side pairs within the Electric Engine Room aft of the Reciprocating and Turbine Engine Rooms, just forward of where the propeller shafts exited the hull. Two smaller 30kW emergency dynamos were located five decks higher up in the ship, and could function to provide emergency lighting in the event of catastrophic flooding around the propeller shafts putting the main dynamos out of service. A completely independent emergency lighting circuit could provide limited illumination in the event that the main lighting circuit was out of commission.

A ship of any size requires strength, stability and structure. The principal longitudinal strength centres on the keel, which in each Olympic-class vessel was a massive built-up construction of steel plating 1½in thick amidships and just under 1¼in thick at the bow and stern. Resembling a beam lying on its narrow edge, this vertical keel was 53in wide and 63in high, increasing in height to 75in in the Reciprocating Engine Room to provide additional strength to carry the massive reciprocating engines.

Four smaller longitudinal members running parallel to the keel on either side provided additional strength in a fore-and-aft direction, and vertical steel plates running in a cross-ways direction between them completed the bottom. From the outer curve of the bottom extending outward and upward were the ship's frames, resembling a series of parallel ribs. These were constructed of 10in steel channels and were spaced 36in apart amidships, with the spacing gradually reduced to 27in at the stern and 24in at the bow where greater strength was needed to withstand the pounding of heavy seas as well as any light ice that might be encountered in New York Harbor in winter. Completing the framework of the hull were web frames called stringers or 'side keelsons', which connected the frames in a longitudinal direction and which gave added belts of great strength along the hull.

The outer skin of each ship was its shell plating – large steel plates riveted to the frames. On average, the shell plates were 6ft wide and 30ft long and weighed between 2½ and 3 tons each, with the largest being 36ft long and weighing 4¼ tons. The thickness of the plates averaged 1in amidships and thinned toward the ends but was thicker in other areas depending on the need for extra strength. The shell plates were fastened with rivets that were applied both by hand hammering and hydraulic press. It is a common misunderstanding that all of the rivets were hydraulically applied. In fact, hydraulic riveting had its limitations – for example, the massive jaws of the hydraulic riveting machine could not be worked around more than moderate bends in the plates or get into confined areas. More than half a million rivets were used on each double bottom, and the weight of these rivets alone was estimated to be 270 tons. When completed, each ship had about 3 million rivets with an estimated weight of over 1,200 tons.

Much has been made in recent years of steel that became overly brittle in freezing temperatures, with suggestions that Titanic was somehow flawed in her construction from the start. In reality, the shell plating and the rivets that held them together and fastened them to the ribs were, in the collision with the iceberg, subjected to shearing forces that they were never designed to withstand. Inspectors from the British Board of Trade – an entity entirely separate from the shipyard and beholden to no private firm – rigorously inspected the ship's riveting in an ongoing basis for tightness and integrity, and any that failed inspection resulted in a deduction from the riveters' wages. While these steel plates were tremendously strong, the term 'shell plating' is quite appropriate as they were only intended to form the ship's outer shell and were never designed to be impervious to any major collision such as with another ship at speed – or an iceberg.

The lowest part of the hull was formed not by a single layer of steel plating, but by the heavily reinforced bottom structure with the keel as its backbone. With the outer bottom plated with steel to form the 'skin' of the ship and the inner bottom also plated, a cellular 'double bottom' resulted. The inner bottom was termed the Tank Top, so named because the double bottom, divided as it was by the keel and its longitudinal and transverse members, was comprised of forty-four separate watertight compartments. These compartments were used as tanks to carry water for ballast, boiler feed, and for domestic use. In addition to holding water, the double bottom added to the safety of the ship. As the Tank Top formed a second skin, it could save the ship from sinking if the ship struck a sunken obstruction or ran aground. Even with the outer bottom torn open, the watertight inner bottom would limit the flooding to the tank space and prevent entry of water into the holds or machinery spaces.

The principal safety feature of the Olympic-class ships, and certainly the one that gave rise to the 'unsinkable' myth, was the division of the space within the hull into sixteen watertight compartments by strong transverse watertight bulkheads. The forward, or collision, bulkhead was carried as high as C Deck, whereas those from the forward end of the reciprocating engines and aft were carried to D Deck. The remainder of the bulkheads – the ones between the boiler rooms amidships – only went as high as E Deck, but the lowest of these (there being a slight rise, or sheer, fore and aft from amidships) was still almost 11ft above the maximum-load waterline. This arrangement would allow Olympic and Titanic to easily survive a breach of two adjacent compartments amidships, the damage that would be expected through a collision with another large ship. Furthermore, each ship was capable of remaining afloat with all of the first four compartments flooded, providing ample protection if the ship rammed a floating body in her path. Thus Olympic and Titanic's builders and owners were confident that their ships would remain afloat even in a worst-case collision scenario, and in fact the ships' watertight subdivisions met and exceeded many of the regulations for large ocean-going passenger vessels of today. In short: an Olympic-class ship would not be easy to sink.

Access through each of the transverse watertight bulkheads was gained by means of vertical-sliding watertight doors, which were held in the open (upper) position by a friction clutch. The doors could be released by means of a powerful electromagnet that was controlled by a switch on the bridge. These doors could also be closed by a releasing lever at the door itself, or from the deck above. The doors were also coupled to a float-activated switch that would close them automatically in the event that the compartment flooded and the water reached a pre-determined level. Although the speed of each door's descent was controlled by a hydraulic cylinder, the system was engineered to permit the doors – which weighed nearly three quarters of a ton – to drop the last 18 to 24in unrestricted. This ensured that they would crush or cut any obstruction (such as chunks of coal) which remained in the doorway, which was especially important since several of the watertight doors gave passage through the coal bunkers.

Any ocean-going ship must be designed to rid itself of water that makes its way into the lower part of its hull, and even the watertight Olympic-class ships were no exception. A complex arrangement of piping connected to drain wells along the centreline of the ship in each watertight compartment provided for the removal of water in any area; a slight upward rise of the Tank Top from the centreline outward on each side ensured that any water would naturally flow into the wells. If necessary, the ship's entire pumping power could be brought to bear on a single compartment, and in an emergency, large volumes of water could be removed from the engine room by utilising the powerful condenser-circulating pumps that cooled the steam from the engines into water that was piped back to the boilers. Combined, either ship's pumping system could move 1,700 tons (over 400,000 gallons) per hour.

Olympic and Titanic were each fitted with a cast-steel rudder with a weight of 101¼ tons, an overall height of 78ft 8in and a width of 15ft 3in. It is commonly believed that Titanic's rudder was undersized and was one of the critical design flaws that contributed to the ship's inability to turn away from the iceberg in enough time to avert disaster. Like many 'facts' that often appear in print and online, this is a fallacy. Unlike warships, which had as a design requirement the ability to manoeuvre quickly, ocean liners had no such requirements. When manoeuvring in a narrow channel they normally utilised their engines in conjunction with the rudder, such as going half ahead on one engine while backing slow on the other. In a 1997 report by the Marine Forensics Panel of the Society of Naval Architects and Marine Engineers, naval architects Chris Hackett and John Bedford stated that: 'It must also be remembered that, although the rudder area was lower than we would adopt nowadays, Olympic's turning circles compare favourably with today's standards.' Their conclusion was based on hard data rather than the speculation and conjecture on which statements to the contrary have been based.

---

Excerpted from Titanic or Olympic by Steve Hall, Bruce Beveridge, Art Braunschweiger. Copyright © 2012 Steve Hall, Bruce Beveridge & Art Braunschweiger. Excerpted by permission of The History Press.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.

---