26/9-14

Position: 87 47.9' N, 173 39' E, temperature - 8 C, air pressure 1007 hPa, wind 8 knots from ENE.
Contacted old hands with long industry experience from marine seismic surveys. Most suggestions pointed to the solenoid valve which controls air flow, but Einar Gjestrum who last worked with Bolt airguns for GECO about 30 years ago was more specific. It is "O-ring; part number 640", he said, and that was really the problem. When started cold, the belt driven hydraulic
pump struggle, because of the viscosity of cold oil. This means that we have to pre-heat both the compressor and the hydraulic oil reservoir every time we need to recharge the air tanks for the airgun. It is cumbersome, but not a logistical problem. Removed ice from the radiation flux instruments. Audun put up a tarp over the store room.