June 17, 2024

Overhaul of Niigata Main Engines and Z-Peller Work

Project Overview

A comprehensive overhaul project was successfully completed on a tugboat equipped with two Niigata 8L28HX main engines and Z-Pellers whilst the vessel was in dry dock in the Port of Dunkirk, France. The client required extensive 24,000-hour major overhauls, as well as replacements for the ZP-41 prop shaft and swivel seals on the 15-year-old tug which operates in the River Medway and Thames Estuary.

Scope of Work

The major overhauls were conducted in accordance with the engine manufacturer’s specifications. The process involved the removal, disassembly, cleaning, inspection/testing, and overhaul or replacement of various components, including:

  • Cylinder heads
  • Rocker assemblies
  • Pistons and connecting rods
  • Liners
  • Camshaft lobes
  • Fuel injectors and pumps
  • Main bearings
  • Fuel feed pumps
  • Lube oil pumps
  • Water pumps
  • Charge air coolers
  • Exhaust manifold

In addition to the engine work, the project also included the renewal of swivel and propeller shaft seals on the port and starboard Z-Pellers.


Upon completing the overhaul, comprehensive sea trials were conducted, meeting the satisfaction of the Superintendent and the vessel was returned to service without delay.

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