Selsam Super Twin Removal

By Paul Gipe

The turbine had failed sometime in the spring of 2009. We were living in Canada for most of the spring and early summer. When we returned it was the fire season and we didn’t drive onto the site because of the high fire hazard.

Why or how the turbine failed is uncertain. At least one diode in the diode bridge was blown. There were signs that one of the air heaters had been hot as well.

When we lowered the turbine the shaft turned roughly and was very stiff. One of the leads to the alternator had burned off all its insulation. There was a lot of bird shit on the alternator. This can be seen in the photos. Whether the bird shit had anything to do with the failure is unknown, but doubtful.

The blades looked remarkably good.

All in all the turbine was in the air for more than a year.

Nevertheless, because of the size of the machine and the limitations of my test equipment, I was never able to complete a full power curve. Much of my equipment was more than ten years old, third hand, and the software had always been problematic. Because of glitches in the logger and in the software, I couldn’t complete the tests.

I am now in the process of upgrading my equipment to current standards.

After more than one year in the air, the blades look surprisingly good. Here the end cap has lost its enamel coat.

Here there is some chipping on the leading edge at the tip.

Bird shit, and lots of it, cascading down the side of the truck alternator.

The shaft was stiff and turned rough. Here one of the leads has burned completely through its insulation.

One of the leads to the alternator burned completely through its insulation.

Diode bridge with the one diode on the right blown with melted insulation.