HMS TERROR, 1845, UPPER DECK PLAN (AS FITTED)

The last technical plan required for HMS Terror is the upper deck, which I have finally completed.

Please note: This plan has been updated - please consult my later posts.

The original 1836 and 1839 deck plans for HMS Terror show the outlines of the ship with planking installed. Therefore, on my plans, I have included the outline of the frames as well as the planking to better facilitate construction. Like the original plans, the position of the solid chock channels accounts for tumblehome. Because the 1839 plans depict HMS Erebus, my plans are based on the 1836 upper deck plans for HMS Terror, but the deck furniture is the same type and style as drafted on the 1839 sheets (see previous posts for rationale). Similar to the profile plans, the position of the deck furniture is based on the 1836 sheets. The most substantial modifications to the plans are at the stern - to accommodate the new position of the rudder and the well for the screw propeller. As a result, the central structure on the stern containing the cistern, color boxes, and water closet was removed from these plans (presumably these were moved to the position of one of the chicken coops). These modifications are also depicted in a contemporary image of the Erebus drawn by Owen Stanley, which shows two large structures on either side of the vessel at the stern.

Parting company with Erebus, 4 June, 1845, Courtesy National Library of Australia.

The deck planking on the vessels was unusual and was not shown in any contemporary plans. Rice (Ross 1847), the shipwright responsible for the refitting, described them in detail:

A contemporary model of HMS Erebus displays that the upper layer of deck planking angled outwards and forwards from the central planks towards the bulwarks. This style was also used for the upper deck of HMS Investigator, which searched for the Franklin vessels on two voyages between 1848-1853. Investigator’s upper deck plan shows that the planking was placed on an angle about 45 degrees from the centerline. On my plans, the width of the central planks is based on the 1839 midships cross section, but the width of outer planks is not described in any contemporary sources and required more research. Fortunately, an archaeologist at the Canadian Museum of Civilization has recently identified a piece of 3 inch thick “fir” deck planking that she demonstrates is very likely to be from one of the vessels (if so it is the only piece of the ships known to currently exist). The plank is exactly 7 inches wide; therefore this is the dimension I use on my plans.

References:

Ross, Sir James Clark
1847 A Voyage of Discovery and Research in the Southern and Antarctic Regions, During the Years 1839-1843: Volume I. John Murray, London.