Titanic – Mark Chirnside’s Reception Room

FAQ: Titanic‘s Weight: How Much Did Titanic Weigh?

Gross tonnage is NOT a measure of weight

There is a lot of confusion about the subject of Titanic‘s weight, which is not helped by some of the terminology used. We often see references to the ship’s ‘gross tonnage’. However, despite what the term implies with the use of the word ‘tonnage’, it is not a measure of weight. It actually measures the total enclosed space within the ship’s hull and superstructure. Therefore references in the media which refer to a comparison of ‘gross tonnage’ and to Titanic being approximately 1,000 tons ‘heavier’ than her sister Olympic are completely inaccurate (and all too common).

The total weight of the ship (displacement) was calculated as 52,310 tons when she was loaded to her designed draught of 34 feet 7 inches – precisely the same as her sister Olympic. (Their larger, younger sister ship Britannic had a displacement of 53,170 tons and the same designed draught.) This was made up of the lightweight (the weight of the ship herself, including her hull, engines, machinery and permanent fittings before she was loaded for sea) plus the deadweight (the weight of the cargo loaded onboard, including everything from her human cargo – passengers and crew – to the coal, other supplies for the voyage and commercial cargo carried in the ship’s holds). These figures are all given in the British, Imperial measure.

This data is taken from shipbuilder Harland & Wolff’s records and summarised below. We see that Titanic in an unloaded condition weighed 480 tons more than her older sister Olympic and that her deadweight was correspondingly smaller. However, both ships’ total weight (displacement) was the same assuming that they were loaded to their designed draught.

It is important to understand that, despite all the confusion in secondary sources (such as articles, books, television programmes and so forth), the primary source evidence (original, contemporary documentation) is all very clear in regard to how much the ship weighed. The ship’s displacement is confirmed in multiple original documents, including Harland & Wolff’s records; Olympic‘s displacement scale (which shows how much water she displaced at a given draught); and the Board of Trade. It is benchmarked against figures Thomas Andrews provided for Olympic in 1911.

FAQ: Was Titanic’s Starboard Propeller Used to Repair Olympic after the Hawke collision?

No.

The available evidence indicates that Harland & Wolff used three spare blades as replacements for the three damaged blades on Olympic’s starboard propeller.

George Cuming, one of Harland & Wolff’s managing directors, was one of a number of professionals to see Olympic in drydock. On 14 October 1911, he summarised the necessary repair work to an Engineer Commander, whose report went to the Director of Dockyards (on behalf of the Admiralty) some days later.

Olympic’s Starboard Propeller Blades

There was some good news: ‘There are no marks on the propeller blades of the centre and port shafts to show that these have been touched by anything at the time of collision’. Unfortunately, the starboard propeller blades were all damaged:

The three blades have been removed; they are damaged towards the tips. They are probably bent as well although this is not obvious. Mr. Cummings’ [sic] proposal is to scrap these three blades, appropriate three spare and replace the spare blades used. The blades are…manganese bronze.

Olympic’s Starboard Propeller Boss

The starboard propeller boss itself (the cylinder at the centre of the propeller to which the blades were attached) was ‘apparently undamaged’ but either of Titanic’s port or starboard propeller bosses were available to use as a replacement in the event that any damage to Olympic’s starboard propeller boss became apparent later. (There is no evidence that it did.) Harland & Wolff proposed to ‘anneal the studs for securing the blades, and if necessary, to renew them’. (To ‘anneal’ meant to heat the material and then allow it to cool slowly, which made it easier to work. In the event, it was necessary to renew at least some of them.)

Olympic’s Starboard Propeller Shafting

There was damage to Olympic’s propeller shafting, but Harland & Wolff did not think any bent shafting could be straightened out or repaired. Instead, it would need to be replaced:

The tail shaft can be withdrawn into the dock and so removed to the shop, the three pieces forward of this necessitate that certain plates should be removed from the ship’s side so as to pass them out into the dock and so send into the shop.

Where the shafting passes through [watertight] bulkheads, the plating has had to be cut in order to uncouple and pass the shafting to be removed through the orifice being cut in the ship’s side.

It is not expected that these four lengths will be in the shop for another seven or eight days, and so the renewal necessary as regards them is unknown. As a precautionary measure a forging has been ordered for one length of shafting. The shafting is hollow and Messrs. Harland & Wolff do not consider that if any length is bent it can be made serviceable by straightening.

The Titanic’s shafting is available if necessary but if used would entail considerable delay in that ship’s completion, as the engines are now being put into her.

While Olympic was in dry dock, Harland & Wolff took the opportunity to increase the pitch of her port propeller blades from 33 feet to 34 feet 6 inches. The cost was accounted for separately to the repairs of the collision damage. The new starboard propeller blades were undoubtedly set at the same pitch.