TRMA Tech Feature of the Month
On the casings for the first three funnels, and situated directly against the fore and aft edges of each funnel, sat elongated areas of gratings. These were the foot grates over the Fidley trunks. The Fidley trunks were essentially muti-purpose ventilation shafts. Not to be confused with the large stokehold vents, whose purpose was to provide the massive airflow needed to feed the furnaces, the Fidley vents provided an escape for heated air from the stokeholds. Without them, the stokehold temperatures - which routinely reached 110 degrees under normal circumstances - would have been unbearable for even the hardiest stokers. The Fidley casings also provided for the firemen's escapes to E deck, ventilation shafts for contingent lavatories, and WC's as well as providing space to run auxilliary steam pipes and those fittings generally intended to be kept separate from the passenger compartments.
As shown below, the stokehold vents provided entry for the massive airflow demanded by the boiler fires. The schematic below shows the air intake in blue, running to the boiler rooms via the fan trunks. At the base of these trunks were large fans that were controlled from the stokeholds below. The fans could increase the airflow as necessary, depending on how hot the fires were being stoked and how much air they required. The exhaust gas from the boiler fire is shown in grey, and the escaping heat out the Fidley trunks in red.
Modeling the grates over the Fidley trunks is covered in the Rivet Counter Tutorial in the Funnels section.
Have a question on this item? Post it on the TRMA Titanic Forum.
Copyright © Titanic Research & Modeling Association