Single Cylinder plants
These are usually found on short run ships such as passenger ferries although there present day use is very restricted
For this design criteria the Single Cylincer Double Casing turbine was developed
Advantages of using A single cylinder
- Lower first cost
- Easy to inspect and maintain
- No cross over pipes to give heavy side thrust
- Short warming through time, rapid shut down time
- Rapid manouevring
- Single setting gland control ( glands are operating subatmospheric all times)
Advantages of using A double casing
- As the glands operate on the low pressure side of the turbine they may be of simplified and shortened design
- The outer casing temperature is only slightly above engine room temperature simplifying lagging requirements.
- The outer casing may be fabricated from mild steel
- Radiation losses reduced at full power
- Smaller temperature gradients reduce the possibility of distortion
- All expansion/contraction and side thrust is absorbed by the inner/other casing interface reducing the possibility of misalignement to the gearing