What is this speedo off?
 

What is this speedo from. Standard military size but what vehicle would need mph and knots? Can't be a boat - nothing needs top speeds that high. Can't be a plane - nothing needs top speeds that low. Hovercraft? Jet powered DUKW? Maybe it is from a Navy jeep to help them feel at home?

Well it's definitely not a DUKW or a GPA. They have ordinary road speedo's. An LVT ( Buffalo) only has a cruising speed of 5 knots, so I doubt it's that? Intriguing! Someone will know I'm sure. Ron

Hi Lang,

The speedo is probably for a speed boat, I have seen some before, calibrated in MPH as well as Knots.

Re. Speedometer
 

Hi all - a bit of Googling research leads me to think this is a boat, sail or speed, speedometer where one can translate the water speed (knots) to a land speed (mph).

Bob

Yes, a boat was my initial thought but even for a speed boat the ranges are useless. The area of 99% of operations below 20knots is too small a scale to be useful. A race boat maybe?

I am going to buy this on ebay out of interest as I can not see the drive. It could well be an aircraft instrument out of something like an early glider if it is a pressure instrument and not mechanically driven but even then 60mph is a bit light on. Maybe a blimp or early helicopter? If it was a race boat it also will be pressure driven.

I even thought a wind gauge out of a control tower but once again 90% of wind speeds are below 10 Knots so once again useless.

If you look at the scale it is almost certainly pressure driven as the numbers get further apart the higher you go - mechanical is a fixed ratio. Water pressure should be constant too so it looks like some air pressure driven device.

Speedo
 

Would something like a Sutherland Flying boat or the like be a possibility?

Regards
Lionel

Lionel,

Sunderlands were slow but cruised at double the speed of the instrument.

Perhaps an e-mail with picture to Stewart Warner would get you the application? If not that - a company that restores vintage instruments could help find it's usage I would bet.
http://www.stewartwarner.com/index1.html

Cheers,

Craig

My Guess
 

My Guess, and it is a guess, is a speed indicator for a ski boat.
A fairly accurate speed indication is important for activities such as bare footing. Most older ones I have seen go to 60mph.

I just won it so when it arrives I will report!