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Interalp (Russian)

Front View: Closed Rear View: Closed
Front View: Closed Rear View: Closed
Front View: Open for Rigging Rear View: Open for Rigging
Front View: Open for Rigging Rear View: Open for Rigging

Technical Details

I acquired my Russian Interalp from an unidentified caver at the 1997 International Congress of Speleology. This was the same caver who sold me the Altius, Version A.

The Russian Interalp is 198 mm. tall, 91 mm. wide, 24 mm. thick, and weighs 207 g.

The shell is a tall irregular shaped stamping made from 3.8 mm. aluminum alloy sheet metal. A 15 mm. diameter rope channel is formed in the upper portion of one side and a smaller cam channel lies opposite. A hole drilled through both sides of the cam channel accepts a 6 mm. semi-tubular rivet. The cam and cam spring are mounted on this rivet. The handle below the cam has a two-piece hard black plastic hand grip riveted into place. The hand grip has four finger grooves. A 15.1 mm. sling attachment hole lies below the handle opening. This hole is not beveled. A 22.7 mm. tall, 15.7 mm. wide hole passes through both sides of the rope channel, providing an attachment point just above the cam. This hole is not beveled either, and a carabiner placed in this hole will probably drag on the rope.

The cam is a plated skeletonized steel casting. The cam radius increases from 39 to 52 mm. over an angle of 33°, giving a 26° cam angle. The cam has number of small conical teeth, all of which have their axes sloping downward. The tooth pattern is (3.4)^3(3.2)^2(1). The top three teeth are almost ground away. Like most eccentric cam ascenders, the inner cam face radius reduces from top to bottom to accommodate various sized ropes. A spring-loaded manual safety bar is mounted on the bottom of the cam. The normal action of the spring holds the safety against the cam. When the cam is opened, the shell interferes with the safety bar, thus preventing opening the cam. If the safety bar is moved away from the cam (opposing the spring), it will clear the shell and the cam will open. At full open the safety can be released and the spring will hold the safety against the back of the shell. This provides a means of locking the cam open. A knob on the safety bar assists in operating the safety mechanism.

The ascender has "INTERALP" molded into one side of the grip and "Tested 5000 N" into the other.


I was only able to get a right-hand ascender. The frame and grips are moderately well made, but the cam casting is poorly done.

This ascender is quite similar to the Altius.