Manufacturer part #: PT-1M
The gauges measure tension over a range of approximately 5% to 25% of the breaking strength of the cable and provide an accuracy of + or - 5%.
| Part No. | Description |
|---|---|
| Model PT - 1 | Cable Sizes 3/32", 1/8", 5/32" |
| Model PT - 2 | Cable Sizes 3/16", 7/32", 1/4" |
| Model PT - 3 | Cable Sizes 1/4", 9/32", 5/16", 3/8" |
| PT - 1 Metric | Cable Sizes 2.5mm, 3mm, 4mm |
| PT - 2 Metric | Cable Sizes 5mm, 6mm, 7mm |
| PT - 3 Metric | Cable Sizes 7mm, 8mm, 9mm, 10mm |
Higher accuracy and easier to use than standard models. The cable can be adjusted while the gauge remains on the cable. "Just watch the pointer move." All readings are based on 302/304 1x19 S.S breaking strengths.
Hold the gauge with the left hand and place the cable between the two nylon spools as shown in Figure 1.
With the right hand pull the lanyard and extend the spring until the hook on the nylon slider can be hooked on the cable as shown in Figure 2.
Release the lanyard. Read the needle position on the scale. Refer to the calibration table obtain correct tension in the cable. The gauge can be left on the wire for "hands free" adjusting of the cable.
To assure accurate readings make sure that the slider moves freely in the frame slot and does not bind. Also, lubricate the slider slot frequently with silicone lubricant.
Note: An extra 1/4" inch hole is provided in the frame of the instrument for an attachment of a short lanyard and snap hook (not furnished) for securing the gauge to the cable. This will prevent loss of the instrument if it becomes inadvertently detached.
How Much Tension
Table 1 recommends an initial tension setting, but there is no simple solution since the optimum rigging tension will be a function of the boat design, the rig (masthead or fractional, one or more spreaders, etc.), and even the cut of the sails. Many skippers use insufficient tension because of a fear of "breaking something." It should be noted that on America's Cup contenders, where electronic state of the art tension instrumentation is available, the standing rigging is set as tight as is structurally feasible.
| Table 1 | |||
|---|---|---|---|
| 302/304 1x19 Stainless Steel Rigging Cable | |||
| Ø In. | Breaking Strength Pounds | Forestay* Pounds | Shrouds* Pounds |
| 3/32 | 1200 | 180 | 120 |
| 1/8 | 2100 | 320 | 240 |
| 5/32 | 3300 | 500 | 350 |
| 3/16 | 4700 | 750 | 500 |
| 7/32 | 6300 | 1000 | 700 |
| 1/4 | 8200 | 1300 | 850 |
| 9/32 | 10300 | 1600 | 1050 |
| 5/16 | 12500 | 2000 | 1300 |
| 3/8 | 17500 | 2750 | 1850 |
* Suggested initial settings.
One Design Class Racing Sailboats
Most sail makers who produce sails for the one design classes provide each purchaser with specific set of readings on theLoos Model A or Model B tension gauges for use when setting up the standing rigging. This assures that the sails will have the correct shape when the rig is under load.
For the convenience of sailors who wish to upgrade from our Model A or B gauges to the professional model (PT-1, PT-2, or PT-3) gauges we include below a conversion chart so that the same recommended tension can be obtained with the PT-1, PT-2 or PT-3 gauges as with the Model A or B gauges.
| Model A | Model Pt-1 | Model B | Model Pt-2 | Model Pt-3 | ||||
|---|---|---|---|---|---|---|---|---|
| 3/32 | 1/8 | 5/32 | SCALE | 3/16 | 7/32 | 1/4 | 9/32 | |
| 5 | 6 | 10 | 11 | |||||
| 10 | 9 | 15 | 13 | |||||
| 15 | 12 | 14 | 18 | 15 | ||||
| 20 | 16 | 16 | 20 | 16 | 18 | |||
| 25 | 20 | 19 | 22 | 18 | 20 | |||
| 28 | 23 | 21 | 24 | 19 | 22 | |||
| 30 | 22 | 26 | 21 | 24 | ||||
| 35 | 27 | 25 | 28 | 23 | 25 | |||
| 38 | 30 | 28 | 30 | 25 | 27 | 25 | ||
| 40 | 33 | 30 | 32 | 27 | 29 | 27 | ||
| 42 | 33 | 34 | 29 | 31 | 39 | |||
| 44 | 36 | 36 | 33 | 31 | ||||
| 45 | 38 | 38 | 36 | 33 | 6 | |||
| 46 | 39 | 39 | 37 | 34 | 7 | |||
| 47 | 40 | 40 | 36 | 9 | ||||
| 41 | 37 | 10 | ||||||
| 42 | 39 | 11 | ||||||
| 43 | 40 | 12 | ||||||
| 44 | 14 | |||||||
| 45 | 16 | |||||||
| 46 | 18 | |||||||
| 47 | 20 | |||||||
| 49 | 25 | |||||||