gulfstreamI

Anyone out there who's tried this sub?

Got this in a trade. It's called the Explorer 7 submarine by Undac Corp. Made in Korea 1987. It's hull is a mix of late WW2 and early 50's submarine and has an oval front profile unlike modern circular /torpedo shaped fast attack subs.
It's got Four (4) size 280 dc motors with impellers similar to water pumps. It's powered by 4 AA's & 2 D size 1.5 volt batteries.
When tested if it works in the bathtub, it was sooooooo quiet! It's apparently using a very crude form of 'caterpillar drive.' (I've been looking for a quiet sub for a long time) There are no exposed props on this sub. I moves quitely thru the water forward, left, right, dive & surface. Another thing, this sub's ballast appears to have been factory pre-set. There are no tiny weights or ballast rings to fiddle with to get the bouyancy just right. It floats perfectly balanced in cold bathtub water. A few pics with side by side comparison to my Nikko subs (Explorer & Sea Wolf)

subcaptian

how much is it? iv benn looking for an affordable sub for a long time now.

gulfstreamI

About 50 bucks. The explorer 7 submarine is slow.... slower than the Nikko subs. It's two advantages is that it can almost turn on it axis. This sub can outurn the Nikko subs. The other is it's quiet "caterpillar drive" that I mentioned earlier. I was able to creep up the Explorer 7 sub to a duck submerged and surfaced right next to it before it flew off! This is stealth at it's best.

RSEA

Gulfstream,

Can you elaborate some on the "caterpillar drive" you talk about? I am having difficulty picturing what this drive system looks like and how it operates. You said it uses 4 impellers....how does that tie in with the caterpillar drive?[sm=confused.gif]

misfitsailor

My Feedback: (6)

Ducted empellors are indeed called a caterpillar drive. In the novel "Hunt for Red October" that is what the Russian sub used (as now used by the Royal Navy Trafalgar-class, the US Navy Seawolf-class, and the French Navy Le Triomphant class) The drive system "used" in the movie version was Magnetohydrodynamic drive or MHD propulsors.

From Wikipedia, here's a boat that used such a drive:

Yamato 1, is a boat built in the early 1990s by Mitsubishi. It uses a magnetohydrodynamic drive, driven by a liquid helium-cooled superconductor, and can travel at 15 km/h (8 knots).

The Yamato 1 was the first working prototype of its kind. It was completed in Japan in 1991, by the Ship & Ocean Foundation (later known as the Ocean Policy Research Foundation). The ship was first successfully propelled in Kobe harbor in June 1992. Yamato 1 is propelled by two MHD thrusters that run without any moving parts.

MHD works by applying a magnetic field to an electrically conducting fluid. The electrically conducting fluid used in the MHD thruster of the Yamato 1 is seawater.[1]

In the 1990s, Mitsubishi built several prototypes of ships propelled by an MHD system. These ships were only able to reach speeds of 15 km/h, despite higher projections.

The Yamato 1 on display in Kobe, Japan

A MHD thruster from the boat, at the Ship Science Museum in Tokyo

Ralph Reyes

Would you by chance have a manual for the Explorer 7
sincerly
Ralph
[email protected]

Harquebus

Effectively harassing waterfowl is one of the benefits I had not considered before.

Neat submarine and great find. Would love to see some pics of it in its natural environment....