"Modern Marvels: Titanic Tech" Questions
Copyright © 2003 by Parks Stephenson
The following is a list of questions that was sent to me by the producer of the "Titanic Tech" installment of the History Channel's popular Modern Marvels series before my on-camera interview for the programme. The questions were intended only to allow me to organise my thoughts before the interview, not to be indicative of what would be used in the final script.
I prepared answers to these questions at home, going into greater detail than required on the questions that interested me the most. Knowing that the other interviewees were going to be covering similar ground, I left other questions unanswered or partially answered. By the time I was interviewed (I was last in the rotation), the producer needed only to ask me a fraction of the questions from the original list. A relatively small subset of those questions survived the editing process to the final cut.
Therefore, the following questions are not meant to be representative of the script for "Modern Marvels: Titanic Tech," which first aired on the History Channel on 01 April 2003. As "talking points," they are also not meant to be thorough answers to the questions raised. Source referencing is not noted. Those familiar with this website will note that I lifted some answers directly from my FAQs page. Despite their informal nature, though, I thought my notes might be of some interest for researchers who would appreciate a starting point for deeper research.
The opinions expressed below are my own and do not necessarily reflect the opinions of the History Channel or the other contributors to that programme. A DVD copy of the programme can be ordered by clicking here.
- Parks Stephenson
1. What was the single greatest technological flourish on the Titanic? Was there anything particularly unique about it or was it just well hyped?
I am of the opinion that the Olympic-class liners were state-of-the-art, large emigrant ships that combined compromise, technology and comfort into an aesthetic design. Titanic, in and of herself, represented no new advance in technology as she was but the younger of two "twin" sisters, with the Olympic being the elder of the two. I think that Titanic was well hyped before she sailed in order to generate interest in a new, yet familiar, ship. Since her sinking, hype has transcended into myth, the so-called "Ship of Dreams" obscuring the reality.
If I had to pick one system used in Titanic as a great technological advance, I would choose the Marconi wireless apparatus. The Marconi Co. provided Titanic with the first rotary spark discharger, a device that represented a transition from the brutish nature of plain spark gap to a more refined method of transmission that would be realised with the later advent of continuous-wave technology.
2. How did the Titanic represent and catalogue achievements of the "Golden Age" mass production of steel, steam engine, electricity, the telephone, radio, etc.
Talk to this, if need be more specific details are provided in response to other questions below.
3. How was Titanic the culmination of shipbuilding expertise accumulated over the last fifty or so years?
The Olympic-class ships certainly benefited from lessons learned as the art of shipbuilding progressed. Refined methods of steel manufacturing that improved the quality of structural components, the use of steam engines to increase the efficiency of manufacturing processes, the advent of electricity to assist in the operation and control of larger hulls, the list goes on...talk to this, if need be.
More important to Titanic's development, though, was the increase in emigrant traffic across the Atlantic. Increasing revenue potential had more to do with the exponential increase in passenger ship hulls during this time than actual technological advances. For that reason, Titanic's size outdistanced her technological capabilities in some respects; e.g., Titanic was, for all practical purposes, unable to physically launch enough lifeboats to hold her expected capacity in any reasonable length of time.
4. Was there a meeting at which Titanic was conceived? Who was there?
After dinner in 1907 at his London home, Lord Pirrie and his guest, Bruce Ismay, began discussing the changing fortunes of the White Star Line. In 1898, the Line's flagship, the H&W-built Oceanic, took the shipping world by storm. She was in the vanguard of technology and proved to be enormously popular. Oceanic and her sisters made the White Star Line world famous and a serious threat to their main competitor, the Cunard Line. Cunard replied in 1906 with the superliners Lusitania and Mauretania, and White Star began to suffer a decline in bookings as a result. Ismay and Pirrie needed to respond if they wanted to regain the lead over Cunard.
It is interesting to chart the progression of size during this period. Each major step forward appeared to represent tens of thousands of tons, all within the space of just over a decade. Oceanic entered into and set the standard for 20,000-ton ships. Lusitania upped the ante by venturing into the 30,000-ton range. Olympic leap-frogged White Star by establishing a 40,000-ton benchmark.
5. Describe the process of building the Titanic, beginning with the steel hull? Were there any adjustments needed to accommodate its size? What was going on with the Olympic at the time?
The keel for Ship No. 401 was laid upon the keel blocks in the slipway on 31 March 1909. The vertical keel plate was then erected, then the double bottom. Half a million rivets alone were used in the double bottom. The tank top was then plated atop the bottom. After that, the rib framing began. After framing was well underway, the deckbeams and stern frame were riveted into place to draw the rib framing into a solid structure. Framing was completed about a year after the keel was laid. The thick steel plates that formed the hull's skin were then riveted to the frame, both hydraulically and manually. Steel rivets were used where the hydraulic riveter could reach; wrought-iron rivets were used where rivets had to driven by hand. Plates were doubled in areas of special stresses. The plating of the structure completed the hull girder and was finished by October 1910, one day before the launch of Olympic. All the while, Ship No. 400 was undergoing an identical process. Having been started three months earlier than No. 401, and enjoying first-born priority, No. 400, christened as the Olympic, would be launched seven months before her "twin" sister, Titanic.
6. Key players Andrews, Carlysle, Pirrie, Ismay. Tell us about them.
Talk to this, if need be more specific details are provided in response to other questions below.
7. What is a double bottom? How is a steel-framed hull built?
It was common practice in warship construction and most merchant ship construction to build an inner skin a certain distance from the outer skin (5 -6 feet in the Olympic-class ships) along the bottom, from the keel to the turn of the bilge and extending almost the entire length of the hull. The space between the inner and outer skin is subdivided in cellular fashion, with the cells functioning as ballast or trim tanks. Each cell was about 3' by 6' between floors and intercoastals, but not every floor and intercoastal was watertight.
White's Manual of Naval Architecture describes double-bottom construction as a "great safeguard." Although the spaces in the double bottom could be used for the stowage of ballast and other convenience, the intent of the double bottom structure was to provide a greater degree of protection against bottom damage.
8. Who built the ship? Tell us a little about Harland & Wolff?
The massive shipyard in Belfast, Ireland, was first laid out on Queen's Island in 1853. It became known by the names of its new owners, business partners Edward Harland and Gustav Wolff, in 1861. The shipyard grew throughout the years, into the start of the next century. Along the way, H&W gained a reputation for constructing high-quality ships that were tailored to an owner's specific requirements. Toward the end of the century, H&W made huge advances in large-hull and steam-engine technology. On 31 July 1908, Harland & Wolff contracted for the construction of two large vessels with the White Star Line.
9. Who owned the ship? Tell us a little about the White Star Line? Who was their chief competitor? How did the competition bear on the creation of the Titanic?
The bankrupt White Star Line was bought by Thomas Ismay in 1867. He immediately formed an exclusive business agreement with Gustav Wolff of the Harland & Wolff shipyard in Belfast. Two years later, Ismay formed the Oceanic Steam Navigation Company, Ltd., while retaining the White Star Line name and house flag for practical use. In 1891, Thomas Ismay made his son, Bruce, a partner in the Line. A year later, the senior Ismay resigned and Bruce took over the Line. In 1902, the International Mercantile Marine Company, run by the American J.P. Morgan, took over the OSNC. Pirrie and Ismay were made directors of IMM's board. Morgan also expressed an interest in the Cunard Line, but in a move to protect British shipping interests, Cunard agreed to a subsidy from the British government in the construction of Lusitania and Mauretania. Bruce Ismay became President of the IMM in 1904 and he, with Pirrie's backing, used his position to promote the interests of the White Star Line. With access to IMM's vast financial resources, the construction of the Olympic-class vessels could be realised.
10. Who designed the Titanic? Where did Carlysle do the work? What was special or unique about the plans? In what ways did the plans differ from the finished ship?
Lord Pirrie developed the requirements for the design of the Olympic-class liners. Alexander Carlisle, Pirrie's brother-in-law and Chief Naval Architect of the shipyard, turned Pirrie's requirements into a practical design. After Carlisle retired in 1910, Pirrie's nephew, Thomas Andrews, completed Carlisle's work.
There was nothing really unique about Titanic's design, as she was built to the same plans used to build Olympic. Olympic herself was in many respects an upscaling of the original Oceanic design. There were, however, superficial changes to Titanic that would differentiate her from Olympic, but these had more to do with interior layout in the passenger accommodation. Talk to this if more detail is needed.
11. How did Titanic differ from her elder sister ship, Olympic? What lessons learned from Olympic's first year in service were applied to Titanic?
Olympic turned out to be too big by some standards in Ismay's mind. In his view, too much space was allotted to public areas. Olympic had two promenade decks that ran the length of the upper superstructure an upper promenade that was open its entire length, and a lower promenade sheltered by screens. Ismay felt that in terms of generated revenue, the space taken by one of the promenade decks would be better be used in the next ship of the class Titanic by enlarging several First Class staterooms and by the addition of the so-called "millionaire's suites" with private promenades and Café Parisien. In addition, space was opened within the Officer's Quarters on the Boat Deck for staterooms reduced by the addition of an enlarged Reception Room for the Restaurant. In addition, Olympic turned out to be under-ventilated. A good one-third of the fans had to be enlarged for Titanic in order to provide proper ventilation for both engineering spaces and passenger accommodation. As mentioned above, the Restaurant proved to be so popular during Olympic's first year that space was cleared in Titanic for an enlarged Reception Room outside the Restaurant, similar in function to the Reception Room forward of the First Class Dining Saloon.
12. It has been claimed by some that Ismay installed screens on Titanic's A-deck promenade in order to protect passengers from spray thrown up by the bow. Is this true?
I don't believe this is true, simply because the screens were never erected to shelter passengers on Olympic's A-deck promenade during her long service life. I concur with Bill Sauder's supposition that the popular reason given for the installation of the screens late during Titanic's fitting-out period was a ruse by Ismay...a means of camouflaging the reduction of public space on Titanic.
13. Was any special machinery needed at the shipyard? (Gantry?)
At the shipyard in Belfast, three previously-used slipways were re-engineered into two larger ones to accept the two new hulls. Four-and-a-half feet of concrete were laid as foundation for the new slipways, in order to support the weight of the two planned hulls. A massive gantry, weighing over 6000 tons and the largest in the world, had to be built over new slipways. The gantry functioned as a scaffolding platform that not only permitting ease of construction over the entire length of the vessel, but also supported a crane that would be used to lift massive tools, like the hydraulic riveter, to the heights needed to complete the hull. The platers' shed had to be re-modelled and re-equipped. The fitters', joiners' and other shops also were upgraded to accommodate the new vessels. A 200-ton floating crane was purchased from Germany and berthed at the outfitting wharf in order the lift the engines, boilers and funnels into the completed hull. A new graving dock, planned with foresight a few years before the Olympic-class vessels were conceived, anticipated the trend toward increased size in ships. Elsewhere, Southampton Harbour had to be dredged to accommodate the deep draft of the new vessels, the Trafalgar drydock had to be enlarged and a new wet dock constructed. In New York, White Star's berthing piers had to be extended by 100 feet.
14. What is the open-hearth method of making steel? Is it a variation on the Bessemer process? Why weren't big ships built before steel mass production?
Steel is iron that has a very exact proportion of carbon mixed into it, making it stronger and less brittle than iron. The Bessemer process was invented in 1855 and was the first practical method for quickly removing impurities (such as silicon, manganese, and carbon) from large quantities of molten iron, thereby allowing for the mass production of steel. This involved pouring molten iron into a large container, called a "converter," where oxidation of the impurities was created by forcing air upwards through the converter. Carbon bonded with the oxygen to form carbon monoxide, which then burnt off at the surface. Silicon and manganese combined with the oxygen to form slag, most of which settled to the bottom of the converter. Steel made using the Bessemer process has a high nitrogen content, is very strong, but brittle at low temperatures. Another, even more efficient process of mass-producing steel was accomplished through the open-hearth process, invented by Siemens in 1856 and first practically applied in 1861, which uses a regenerative furnace to allow wrought-iron scrap to be melted together with cast iron upon the open hearth, instead of within a container. Most British steelworking firms of the early 20th Century using the open-hearth process had acid-lined furnaces, which produced a mild steel with a high content of oxygen, phosphorus and sulphur. It was this type of steel that was used in Titanic, and essentially similar to the steel that would later be used to construct the Queen Mary.
15. How much steel was used on the Titanic and for what? How was the ship riveted together? Were these methods standard for the time? Are they used today?
Over 24,000 tons of steel were used in the building of the hull and superstructure. Almost 1500 tons of that were in rivets (3 million total) alone. As mentioned earlier, both steel and wrought-iron rivets would be used in her construction. The methods used to forge the steel and rivet the ship's structure together were standard in the British shipbuilding industry of the time and would remain so through World War II. Nowadays, riveted structures are rare...welded structures are the norm.
It happens that welding was an emerging technology when Titanic was built. The expansion joints in Titanic were constructed using this new method of joining.
16. Did the builders use inferior steel in Titanic's construction?
The current myth of "inferior steel" evolved from pure hindsight. It is true that the steel provided to Harland & Wolff by Dalzell and D. Colvilles & Co. was produced in acid-lined open-hearth furnaces, which allowed for impurities (such as sulphur and phosphorous) in the steel. These impurities led to low fracture resistance, especially in cold water conditions that reduced ductility (ability of the steel to deform without yielding), by reducing the amount of manganese present to bind to the residual sulphur. With insufficient manganese, the sulphur combined with the iron to form the ferrous sulphide, which created paths of weakness (especially along grain boundaries) along which fractures could propagate. The manganese-sulphur ratio of Titanic's steel recovered from the wreck site has been determined to be 6.8:1, low in comparison to steels produced today that have ratios as high as 200:1. The presence of phosphorous, even in minute quantities, also played a significant role in the initiation of fractures. However, most of steel used by British shipyards during this period was produced using the open-hearth method; in fact, the metallurgy of the steel did not change significantly until after 1947, when wartime experiences prompted closer examination of the elemental properties of steel. At the time of her construction, Titanic's builders used top-quality steel that would remain the industry standard for years to come. To accuse Titanic's builders of using "inferior steel" is unfair, as it would be decades before the minor elements of steel would be more fully understood.
17. Can you explain "microcracking?"
Another factor in the break-up of the ship appears to have been crack propagation along rivet holes. For the Olympic-class ships, the rivet holes were cold punched through the steel plates prior to riveting the plates to the framing. This is an invasive process that creates micro-cracks around the periphery of the rivet holes. In addition, many of Titanic's rivets were hydraulically driven, which created residual compressive stresses that were not relieved, as the cooling of the rivets drew the plate tight against the framing. When the sulphide particles in the steel are subjected to stress, the micro-cracks can coalesce into macro-cracks, which provide pathways for fracture propagation. The British Admiralty subsidised the construction of Lusitania and Mauretania, thereby enabling them to enforce their standing requirement for all rivet holes to be reamed in order to prevent the spread of micro-cracks. After Olympic's collision with H.M.S. Hawke in 1911, Harland & Wolff Naval Architect Edward Wilding noted that cracks had developed in plates that were not located within the immediate impact area. His concern was that the micro-cracks allowed fracturing to propagate and he urged that the Lloyd's Rules for hull surveying requirements be modified to include impact and notched-bar testing. However, even though he recommended that rivet holes be reamed as a precautionary measure, he acknowledged that it was an expensive proposition that would not be cost-effective for steamship companies to implement, given the anticipated loads a steamship might endure during her career.
By 1930, ship classification societies had fully disallowed the cold punching process because of experiences with steamships that were by then getting long in the tooth. Olympic, in particular, suffered greatly from stress crack propagation in her plating, as evidenced in a 1930 hull survey. The Queen Mary used essentially the same steel that the Olympic-class ships used, but she suffers less from crack propagation because her rivet holes were drilled, then reamed.
18. Did cold water weaken Titanic's steel hull?
It wasn't until the T-2 tanker Schenectedy broke in half while fitting out in a shipyard in Oregon during the first part of January 1943 that a concerted investigation was launched into the mechanics of ductile-brittle behaviour at or around freezing temperatures. What we know today about steel embrittlement during cold temperatures comes from the failure rates of Liberty ships and T-2 tankers during World War II the builders of the great transatlantic liners simply did not understand the relationship between temperature and ductility. Even so, plates recovered from the Titanic wreck site show a relatively low ductility in some, but not all, plates. There is not enough evidence to say that embrittlement played a significant role in the initial flooding of the ship. It might have, though, contributed to the manner in which the hull fractured.
19. What is meant by "watertight?" How can compartments be watertight if the walls don't extend all the way up?
In the most simplistic terms, the height of two watertight bulkheads is calculated by taking the volume of the compartment that is created between them and assuming that compartment is completely flooded, subtract that volume from the ship's displacement. If the tops of the bulkheads are tall enough to be above the ship's new load-draft line after losing the subject compartment, then water will not rise over the tops. Even if the affected compartment isn't capped by a watertight deck, the bulkheads are still considered to be "watertight," because they can contain the water coming through the opening in the hull within the compartment between them. This is a simplistic summary of the type of calculation that was performed by Titanic's designers when they determined her internal subdivision. Given Titanic's expected operating environment, the height of her bulkheads should have been sufficient. The manner in which a merchant vessel should have been operated meant that the most serious hazard should have been collision with another vessel. Titanic's internal subdivision was well designed for such an eventuality. What Titanic's designers could never reasonably predict was that her crew would steam full speed through a known ice region and risk running into an iceberg.
After the inquires into the Titanic disaster had run their course, the work stoppage on hull 433 was lifted and work begun anew, albeit with major changes in the new ship's design. One of the most significant modifications incorporated was the extension of 5 of the total 15 watertight transverse bulkheads in the centre of the ship all the way up to B deck (the remainder went up to E deck), dissecting much of the First Class accommodation. Even with the increased subdivision, though, Britannic sank in much the same manner as Titanic with her head pulled down by the loss of buoyancy represented by the flooded compartments, water found its way aft into undamaged compartments through multiple deck and hull openings (of which open portholes played a significant role). Again, a scenario that could not be envisioned by designers laying out a merchant vessel.
20. How big were the anchors? What were they made of? How were they made?
The bow anchors were 7 3/4 tons, the forward anchor about 15 1/2 tons. They were made from steel, rough cast, then hammer-forged into final shape. Each link in the anchor chain weighed 175 pounds.
21. Were there other large parts? Propellers, etc.?
The mild cast steel stern frame was 70 tons. The rudder consisted of 5 sections and weighed over 100 tons. The wing propellers were over 23 feet in diameter and weighed 38 tons. The centre propeller was over 16 feet in diameter and weighed close to 17 tons. The four funnels rose above the boiler room floors an average height of 150 feet.
"Titanic Tech" Questions Page 2