RADFORD 450 - DESIGN #13 - STEEL CRUISING YACHT

DESIGN IS ARCHIVED - RADFORD 450 SUPERCEDED BY RADFORD 460

R450 - DSN#13 - Good Life in Dry Tartugas
L.O.A. 13.70m 45'0"
L.W.L. 13.00m 42'8"
Beam 3.93m 12'11"
Draft 1.70m 5'7"
Dspl 14,500kg 14.3T
SAIL AREA
Main 47.9sq m 515sq ft
Genoa 64.2sq m 690sq ft
Yankee 38.25sq m 411.7sq ft
Staysail 14.9sq m 160.4sq ft

The R450 is another of the Radford 1000 Series steel cruising yachts - designed as a long distance, live aboard cruising yacht with the emphasis on safety, accommodation and sailing ability.

Kit Assembly and Layout Options

The R450 uses the latest in computer design and manufacturing technology to produce steel kits suitable for amateur or professional builders. The range of design and kit options for the R450 include centre cockpit and pilot house layouts; a 2.3m fin keel and a 1.7m shallow draft keel.

Accommodation

R450 - DSN#13 - Good Life - PH accom

The accommodation drawings give an indication of what will easily fit into the space available. As the accommodation does not contribute to the structural strength of the yacht it can be easily altered to suit the owner's requirements. Water tanks are in general located below the cabin sole leaving areas under the settees for gear stowage. The pilot house has more room for fuel & water tankage. The pilot house accommodation with the midship cabin is aimed at those needing lots of berths and is more "congested" than the other two. If the extra cabin is not required the layout would be better with the galley to port and the head and shower to starboard. The centre cockpit layout shows large saloons with wide settees and angled backrests. The galleys are also large with plenty of stowage. The forward vee berths can be converted to a double or, built as single upper and lower berths.

Deck Layout

The pilot house version has large lazarettes with good access to the steering gear and gas bottle stowage under the aft deck. There is an optional watertight bulkhead between the lazarette and the accommodation which would give added safety. The centre cockpit layout has an optional port side lazarette. Both have boarding platforms incorporated into the transom and an anchor locker forward of the collision bulkhead.

In both options permanently fitted companionway doors are specified. Fixed or soft dodgers, or a combination, are used for weather protection on the centre cockpit version.

Sail Plan

The double spreader rig can be used as either a sloop or cutter. The cutter would be favoured for cruising with the staysail becoming the storm jib when required. On the pilot house version the boom is angled up so that the mainsail can be sheeted on the dodger or house top leaving the cockpit clear.

Loading

Waterline Displacement Loading
25mm (1") Up 14,311kg 31,550lb nil nil
@ D.W.L. 15,062kg 33,206lb 751kg 1,656lb
25mm (1") Down 15,828kg 34,895lb 1,517kg 3,344lb
50mm (2") Down 16,608kg 36,615lb 2,297kg 5,064lb
Expected Maximum
75mm (3") Down 17,402kg 38,365lb 3,091kg 6,815lb
100mm (4") Down 18,208kg 40,142lb 3,897kg 8,591lb

The R450 has very good volume and the carrying capacity required for a cruising yacht. The following information shows the range of loading and changes in waterlines.

An effort should be made to build and load the yacht within the figures recommended. Overbuilding or adding any unnecessary weight during construction and fitout will detract from optimum loadings.

Scantlings

R450 - DSN#13 - Good Life - PH accom

The hull structure is designed to the A.B.S. Guide for Offshore Racing Yachts and is basically the same for both layouts with only minor variations relating to the engine positions. Hull frames and floors are spaced at 650mm and regularly spaced 40 x 5mm stringers allow for the use of 4mm hull plating. The frames, backbone and keel base are cut from 8mm plate while the floors and keel plating are 5mm. The skeg, collision bulkhead, deck & house beams etc are 4mm; while the deck, house and cockpit plating are all 3mm. Total steel weight for the plates in the kit - including the hull plates, M.S. flatbar stringers, capping, tubes etc come to approximately 8.25T.

Engines

S/L Ratio Speed - knots SHP
1.00 6.53 29.68
1.10 7.18 39.50
1.20 7.84 51.28
1.3 8.49 65.20
1.34 (maximum) 8.75 71.41

The maximum hull speed of the R450, at Speed / Length Ratio (S/L) = 1.34, is 8.75 knots. An efficient cruising speed is at S/L = 1.1, or 7.18 knots. The list shows the required shaft horsepower (SHP) for different speeds at 16,330kg (36,000lb) displacement. Note the rapid increase in required SHP (hence fuel consumption) for small gains in speed.

Based on a speed requirement, select an engine which - running at an optimum RPM - will give the required SHP for that speed.

In Conclusion

The combination of the rig and hull shape will ensure good sailing performance while the big accommodation space and the strength of the steel hull gives a safe, comfortable offshore cruising yacht.