C134 SAFETY OF LIFE AT SEA 



existing ships, it shall be maintained as near the rated voltage as possible andj 

 if practicable, within + 10 per cent. 



(k) The reserve installation shall be provided with a source of energy 

 independent of the propelling power of the ship and of the ship's electrical 

 system. The Administration may delay the application of the requirement 

 for a reserve source of energy for a period not exceeding three years from the 

 date of coming into force of the present Convention, in the case of existing 

 installations on those cargo ships of 500 tons gross tonnage and upwards but 

 less than 1,600 tons gross tonnage which were excepted, prior to the date 

 of the coming into force of the present Convention, from the requirement to 

 be provided with a reserve source of energy. 



(/) The reserve source of energy shall preferably consist of accumulator 

 batteries, which may be charged from the ship's electrical system, and shall 

 under all circumstances be capable of being put into operation rapidly and of 

 operating the reserve transmitter and receiver for at least six hours continuously 

 under normal working conditions besides any of the additional loads mentioned 

 in paragraphs (w) and (n) of this Regulation*. 



(m) The reserve source of energy shall be used to supply the reserve 

 installation and the automatic alarm signal keying device specified in 

 paragraph (r) of this Regulation if it is electrically operated. 



The reserve source of energy may also be used to supply : — 



(i) the radiotelegraph auto alarm; 



(ii) the emergency light specified in paragraph (g) of Regulation 8 of 

 this Chapter; 



(iii) the direction-finder; 



(iv) any device, prescribed by the Radio Regulations, to permit change- 

 over from transmission to reception and vice versa. 



Subject to the provisions of paragraph («) of this Regulation, the reserve 

 source of energy shall not be used other than for the purposes specified in 

 this paragraph. 



(n) Notwithstanding the provisions of paragraph (m) of this Regulation, 

 the Administration may authorise the use in cargo ships of the reserve source 

 of energy for a small number of low-power emergency circuits which are 

 wholly confined to the upper part of the ship, such as emergency lighting 

 on the boat deck, on condition that these can be readily disconnected if 

 necessary, and that the source of energy is of sufficient capacity to carry 

 the additional load or loads. 



* For the purpose of determining the electrical load to be supplied by the reserve source 

 of energy, the following formula is recommended as a guide: 



J of the transmitter current consumption with the key down (mark) 

 + i of the transmitter current consumption with the key up (space) 

 + current consumption of receiver and additional circuits connected to the reserve 

 source of energy. 



Ch. 4 



