Our V-1 Pulse jet engine adventure.

Why don't planes use pulsejets?

I know why now..

We learned from our failed pulse jet. (True story.)

This is the same type of engine that powered the V1 bombs over London in 1939.

We made one in our mechanical laboratory, after hours, at my mechanical engineering university in Sweden in 1962. (Name withheld, there may still be angry neighbours around looking for us.)

We started with a 25 mm diametre round steel bar, drilled it out and machined the conical areas. It was only two pieces with the round single flapper valve on a stem with a spring in between.

We got full marks for our excellent machining and creating perfect threads.

The spark plug and magneto ignition system came from a “retired” 50 cc moped engine. We took the piston out and put the engine output shaft on an electric drill, held in a vice. It vibrated badly for the lack of the rod and piston but spun freely.

We secured the pulse engine in a bench vice, pointing into the open space.

The fuel was kerosene and we started it by wiggling a compressed air hose in front, held by a hand with an asbestos glove (Who knew about Asbestos then?)

It eventually started, ran with deafening noise and almost blew out the window at the other end of the room, about ten metres away. The room filled with kerosene exhaust.

All windows were open for all runs after the first one.

We run it several times in succession, but only for a few seconds each time. The running problem was to get a steady fuel flow. We never had a chance to correct that little fuel system engineering flaw.

(I wear hearing aids now. Was my hearing loss initiated then?)

We were all infused with kerosene smell and black soot.

This was done long after dark. The building caretaker came and started screaming at us.

We had to come back, wash down the walls, pay for our own paint, and make the walls look better a few days later.

Kerosene made black soot, but you knew that?

We never checked for thrust then, and never had a chance again. It did blow out a lot of black air, though.

I’m sure that one of my colleagues still have the engine, sans ignition system, somewhere.

The question in our department was, should we be punished or congratulated on our “initiative”.

Nobody of authority said anything harsh and we all graduated a year later