Convert Poundal to Long Ton-Force
Convert Poundal (pdl) to Long Ton-Force (tf (UK)) instantly and accurately.
Conversion Formula
tf (UK) = pdl × 1.387542418e-5
About Poundal
The poundal (pdl) is the force unit of the foot-pound-second absolute system - the force to accelerate 1 pound at 1 ft/s² - approximately 0.1383 N. Introduced in 1877 by Thomson and Tait as the FPS analogue of the CGS dyne (1 dyn = 1 g·cm/s²; 1 pdl = 1 lb·ft/s²). The poundal is distinct from pound-force: since standard gravity = 32.174 ft/s², 1 lbf = 32.174 pdl. It survives in older British engineering texts and early 20th-century thermodynamics literature, but is otherwise obsolete. 1 pdl = 0.138254954376 N = 1/32.174 lbf.
About Long Ton-Force
One long ton-force is the gravitational force on an imperial long ton (2,240 lb = 20 × 112 lb hundredweight) - approximately 9,964 N. The long ton was the traditional British ton; long ton-force appears in Royal Navy vessel displacement records, British Admiralty anchor chain standards, pre-metrication UK bridge live load codes, and Australian/South African mining bolt pull-out specifications. It sits between short ton-force (8,896 N) and metric tonne-force (9,807 N) - about 12% heavier than a short ton-force. 1 long tf = 2,240 lbf = 9,964.02 N.
Quick Reference Table
| Poundal (pdl) | Long Ton-Force (tf (UK)) |
|---|---|
| 1 pdl | 1.388 × 10-5 tf (UK) |
| 2 pdl | 2.775 × 10-5 tf (UK) |
| 5 pdl | 6.938 × 10-5 tf (UK) |
| 10 pdl | 0.000138754 tf (UK) |
| 25 pdl | 0.000346886 tf (UK) |
| 50 pdl | 0.000693771 tf (UK) |
| 100 pdl | 0.00138754 tf (UK) |