Thomas 1/4/ Ton II
Description
The Thomas 1/4 Ton II is a 25-foot International Offshore Rule (IOR) Quarter Ton class racing sailboat, a variant of the designs by prominent British yacht designer David Thomas (1932–2014). It belongs to the same family as the original Thomas 1/4 Ton (prototype Purple Haze, 1977) and the related production Bolero model. Like its predecessor, boats in this line were built as one-offs or small semi-custom runs in the late 1970s onward, typically in cold-molded wood (e.g., mahogany by builders such as Bob Hoare) or early GRP/fiberglass. Production numbers for the specific "II" variant remain undocumented and limited, consistent with the handful of competitive custom Quarter Tonners from the era rather than mass production. These lightweight, low-freeboard boats were optimized for IOR racing with an emphasis on light-air speed, upwind performance, and club-level or Cup competition. This rig configuration features a larger mainsail relative to the original Thomas 1/4 Ton.
Construction Details
| Designer | David Thomas |
|---|---|
| Builder | One-offs or small runs |
| Length | 25.000 ft |
| LOA | 25.000 ft |
| LWL | 19.800 ft |
| Beam | 9.000 ft |
| Displacement | 28090 lb |
| Ballast | 1550 lb |
| Year Built | 1979 |
The standard boat dimensions
| i | 30 ft |
|---|---|
| j | 10.25 ft |
| p | 34 ft |
| e | 12.75 ft |
| p2 | - |
| e2 | - |
| i2 | - |
| j2 | - |
| I | J | P | E | P2 | E2 | I2 | J2 |
|---|---|---|---|---|---|---|---|
| 30 ft | 10.25 ft | 34 ft | 12.75 ft | - | - | - | - |
Sails
Thomas 1/4/ Ton II - MAINSAIL
| Luff | * 34 ft - (10363 mm) |
|---|---|
| Foot | * 12.75 ft - (3886 mm) |
| Leech | * 35.73 ft - (10891 mm) |
| Tack Angle | * 88.03 ° |
| Diagonal | * 35.9 ft - (10942 mm) |
| Head (inches) | * 6 in - (152 mm) |
| Area | 216.5 ft² |
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Thomas 1/4/ Ton II - JIBSAIL
| Luff | * 25.36 ft - (7730 mm) |
|---|---|
| Foot | * 13.73 ft - (4185 mm) |
| Leech | * 21.78 ft - (6639 mm) |
| Percentage LP | * 115 % |
| Length Perpendicular | * 11.79 ft - (3594 mm) |
| Deck Angle | * 12 ° |
| Area | 149.44 ft² |
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Thomas 1/4/ Ton II - GENOA
| Luff | * 30.12 ft - (9181 mm) |
|---|---|
| Foot | * 16.69 ft - (5087 mm) |
| Leech | * 28.2 ft - (8595 mm) |
| Percentage LP | * 150 % |
| Length Perpendicular | * 15.38 ft - (4688 mm) |
| Deck Angle | * 4 ° |
| Area | 231.61 ft² |
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Thomas 1/4/ Ton II - SPINNAKER
| Stays | * 30.12 ft - (9181 mm) |
|---|---|
| MidGirth | * 18.45 ft - (5624 mm) |
| Foot | * 18.45 ft - (5624 mm) |
| Perc LP | * 180 % |
| Area | 472.36 ft² |
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Disclaimer. Boats are not all the same -- even when produced in the same factory of the same model. Sailrite does its best to publish accurate dimensions, but we often find it worthwhile to have our customers measure their boats carefully before we produce kits for them. You should take the same precautions, especially when the data is not from Sailrite. The information on this site is not guaranteed to be accurate. Sailrite offers this content as a service to our community, but takes no responsibility for the reliability of the data provided.
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