Page 146 - Practical Ship Design

Weight-Based Designs 113

A suggested list for merchant ships is divided into three groups which are
numbered 6,7 and 8 to follow the sequence of the outfit groups. The items in the
groups are generally arranged on a functional basis, a secondary motive being a
desire to keep items with approximately the same cost per tonne together to
facilitate the use of these groups in approximate cost estimates as described in
Chapter 18.

Group 6. Propulsion machinery
- 6.1 main engine(s)
- 6.2 main engine lubricating oil and water
- 6.3 main engine control systems
- 6.4 gearing
- 6.5 shafting and bearings, etc.
- 6.6 propeller(s)

Group 7. Auxiliary machinev
- 7.1 generators
- 7.2 compressors
- 7.3 boilers
- 7.4 heat exchangers
- 7.5 purifiers
- 7.6pumps
- 7.7 pipework
- 7.8 lubricating oil and water in auxiliary machinery and systems
- 7.9 cranes, workshop plant, spare gear

Group 8. Structure related
- 8.1 floorplatesJadders and gratings
- 8.2 engineers tanks
- 8.3 uptakes
- 8.4 vents
- 8.5 funnel

4.5.9 Detailed nzachinery weight calculations - warships

As already noted, warship designers do not recognise a split in outfit and machinery
and instead use the weight groups shown in Fig. 4.14.
Following a similar procedure to that suggested under outfit, it is convenient to
take the sum of Group 2, propulsion, and Group 3, electrical, as being approx-
imately equivalent to the merchant ship machinery grouping.