D-class lifeboat (Avon S650)
The D-class (Avon S650) lifeboat was a sub-class of 4 inflatable boats operated as part of the D-class between 1971 and 1986 by the Royal National Lifeboat Institution of the United Kingdom and Ireland. It was superseded by the D-class lifeboat (Zodiac III).[1]
| Class overview | |
|---|---|
| Name | D-class (Avon S650) | 
| Builders | Avon Inflatables | 
| Operators | |
| Preceded by | D-class (RFD PB16) | 
| Succeeded by | D-class (Zodiac III) | 
| Built | 1971 | 
| In service | 1971–1986 | 
| Completed | 4 | 
| Retired | 4 | 
| General characteristics | |
| Class and type | Avon S650 | 
| Length | 5 m (16 ft) | 
| Beam | 2 m (6.6 ft) | 
| Propulsion | 1 × 40 hp Evinrude outboard engine | 
| Speed | 20 knots (23 mph; 37 km/h) | 
| Endurance | 3 hours at full speed | 
| Capacity | 10 | 
Utilization
    
There were only 4 Avon S650 utilised by the RNLI as part of the D-class, the workhorse of the RNLI inshore lifeboat (rescue) (ILB) fleet. Significantly smaller in comparison to the rest of the inshore fleet, the D-class is also one of the few RNLI types not to feature a rigid hull. The main aspect of the boat would be both its size and weight, the D-class was specifically designed as a light and highly manoeuvrable rapid response craft.
Design and construction
    
The D-class lifeboat consists of two sponsons, together housing four inflatable segments intersected by baffles.[2]
This was one of the smaller classes of lifeboat operated by the RNLI, and while there were only 4 Avon S650s in the fleet, the D-class were a common sight at lifeboat stations around the coast. Unlike other members of the ILB fleet, the D-class does not have a rigid hull; all others, with the exception of the Arancia, hovercraft and ALB Tenders, are Rigid Inflatable Boats (RIBs).
Fleet
    
| Op. No.[lower-alpha 1] | Name | In service | Principal Station | 
|---|---|---|---|
| D-201 | unnamed | 1971–1973 | Harwich | 
- Op. No. is the RNLI's Operational Number of the boat.
 
References
    
- Leach, Nicholas (December 2009). Harwich Lifeboats: An Illustrated History. Amberley Publishing Limited. ISBN 9781445623498. Retrieved 11 April 2016.
 - "Avon S650". Avon. Retrieved 11 April 2016.