Two emergency repair methods for a broken gear pump shaft are described below:

1. The pump is dismantled, and the broken shaft is removed.
2. Both halves of the broken shaft are machined and polished to fit face-to-face.
3. A small metal pipe with an outside diameter matching the shaft’s diameter is selected.
4. The broken ends are machined down to fit the inner diameter of the pipe.
5. Drill and tap two holes in the pipe to hold pinching screws.
6. Insert the broken shaft ends into the pipe so they fit tightly, making the shaft behave like a single piece.
7. Install pinching screws to prevent movement between the pipe and the shaft.
8. Ensure the total shaft length matches the original, reassemble the pump, and test it.

1. Clean and machine the broken shaft pieces.
2. Preheat both pieces to 320-380°C with a propane or natural gas torch to reduce thermal stress.
3. Use Shielded Metal Arc Welding (SMAW) with low-hydrogen electrodes to join the shaft.
4. Allow the welded shaft to cool slowly to prevent cracking.
5. Machine the welded shaft to match the original dimensions, reassemble the pump, and test it.

Alternative if no spares are available:

The most viable alternative is to utilize a standby pump of similar capacity. If one is not immediately available onboard, an old discarded pump (provided the shaft is in good condition after inspection) could provide a replacement shaft. A portable pump with flexible hoses can also serve as a temporary solution.