Bureaucrat, staff, administrator
4,335
edits
Changes
m
<!-- Fig 5-1 – Bruce Roberts Trawler 55 – full displacement with split accommodation and galley down. One forward cabin is shown as an office
– Graphic with permission © Bruce Roberts Yachts, http://www.bruceroberts.com/
-->
<!-- DeFever 44 – semi-displacement with midships engine room, typical split accommodation and galley up
– Graphic with permission © Nelson Trawlers, http://www.nelsontrawlers.com/
-->
With hydraulic or electrical drive, the engine can be bedded in any convenient spot. It doesn’t have to be inline with the prop shaft. This enlarges the space for the accommodation, and allows more variety in layouts.
Even more space can be reclaimed by placing the engine room aft, and making it smaller, using a mechanical V-drive, hydraulic Z-drive or electrical drive. Rotatable Z-drives eliminate any need for a stern thruster. All of the below deck accommodation will then be forward, substantially simplifying the layout of electrical wiring, plumbing, heating, ventilation and air-conditioning.
→Engine Room
An amidships engine room adversely impacts air-conditioning more than an aft engine room, since there are twice as many bulkheads to transfer heat (and noise). It also complicates heating and air conditioning; and increases the general noise level aboard. Contrarily, putting the mass of the engine amidships helps the centre of gravity. However, overall the optimum layout has the engine room aft.
There are several ways of reducing the impact of the engine room on the arranegment, but they all add cost and complexity. The space occupied by a central engine room can be minimised by using a sideways engine lay-out and hydraulic or electric drives.
[[File:ElectricDriveLayout.png|200px|left|With an electric drive, one engine can be eliminated - the battery bank provides emergency power]]
With hydraulic or electrical drive, the engine can be bedded in any convenient spot. It doesn’t have to be inline with the prop shaft. This enlarges the space for the accommodation, and allows more variety in layouts.
The trade-off is that the drive system is more expensive, from $20,000 to $50,000, and the larger accommodation increases the fitting out cost. So the trawler is substantially more expensive to build. Repair expertise is harder to find for hydraulic and electric drives; although construction and farming use hydraulic extensively.
With an electric drive, build costs can be contained somewhat by using only one engine. If the engine fails, an electric drive can use the house bank for full emergency power.
[[File:EngineLayoutAstern.png|200px|left|With electric or hydraulic drive, or a mechanical V-drive, the engine can be placed astern]]
Even more space can be reclaimed by placing the engine room aft, and making it smaller, using a mechanical V-drive, hydraulic Z-drive or electrical drive. Rotatable Z-drives eliminate any need for a stern thruster. All of the below deck accommodation will then be forward, substantially simplifying the layout of electrical wiring, plumbing, heating, ventilation and air-conditioning.
The main trade-off is in the position of the galley, especially if it has cold-plate refrigeration. A cold-plate refrigerator should be as close as possible to the engine room.