Section 6 Starting arrangements

6.1.1 Equipment for initial starting of gas turbines is to be provided and arranged such that the necessary initial charge of starting air, hydraulic or electrical power can be developed on board the ship without external aid. If, for this purpose, an emergency air compressor or electric generator is required, these units are to be power-driven by manually-started engines, except in the case of small installations where a hand-operated compressor of approved capacity may be accepted.

6.1.2 Alternatively, other devices of approved type may be accepted as a means of providing the initial start.

6.1.3 Where the integrity of the starting system is susceptible to overspeed conditions, appropriate alarm and/or trip functions are to be provided, see also Pt 6, Ch 1 Control Engineering Systems.

6.2.1 Means are to be provided to clear all parts of the gas turbine of the accumulation of fuel oil or for purging gaseous fuel before ignition commences on starting, or recommences after failure to start. The purge is to be of sufficient duration to displace at least three times the volume of the exhaust system.

6.3.1 Where the gas turbine is arranged for air starting, the total air receiver capacity is to be sufficient to provide, without replenishment, not less than six consecutive starts. At least two air receivers of approximately equal capacity are to be provided to satisfy the plant air start requirements. For scantlings and fittings of air receivers, see Pt 5, Ch 11 Other Pressure Vessels.

6.3.2 For multi-engine installations, three consecutive starts per engine are required.

6.4.1 Where the gas turbine is fitted with electric starters powered from batteries, two batteries are to be fitted. Each battery is to be capable of starting the gas turbine and the combined capacity is to be sufficient without recharging to provide the number of starts required by Pt 5, Ch 4, 6.3 Air starting 6.3.1 or Pt 5, Ch 4, 6.3 Air starting 6.3.2.

6.4.2 The requirements for battery installations are given in Pt 6, Ch 2 Electrical Engineering.

6.5.1 Where the gas turbine is arranged for hydraulic starting, the capacity of the power pack is to be sufficient to provide the number of starts of the gas turbine as required by Pt 5, Ch 4, 6.3 Air starting 6.3.1 or Pt 5, Ch 4, 6.3 Air starting 6.3.2.