3286
THE NEW ZEALAND GAZETTE.
[No. 77

ARTICLE 30.
Watchers.

1. A watcher’s certificate shall not be granted by a Contracting Government unless the applicant proves that he is capable—
   (a) Of receiving and understanding the alarm, distress, safety, and urgency signals when these signals occur among a series of other signals;
   (b) Of correct reception by ear of code groups (mixed letters, figures, and punctuation marks) at a speed of sixteen groups per minute, each group being composed of five characters and each figure or punctuation mark counting as two characters;
   (c) Of regulating the receivers used in the ship’s radiotelegraph installation.
2. The Contracting Governments undertake to take steps to ensure that certified watchers observe the secrecy of correspondence.

ARTICLE 31.
Technical Requirements.

The radiotelegraph installations required by Article 27 above and the direction-finding apparatus required by Article 47 shall comply with the following requirements:—

1. The ship’s station must be placed in accordance with the detailed Regulations of the Government of the country to which the ship belongs, in the upper part of the ship in a position of the greatest possible safety, as high as practicable above the deepest load water line.
2. There shall be provided, between the bridge of the ship and the wireless telegraph room, means of communication either by voice, pipe, or by telephone, or in some other manner equally efficient.
3. A reliable clock with a seconds hand must be provided in the wireless telegraph room.
4. A reliable emergency light must be provided in the wireless telegraph room.
5. The installation shall comprise a main installation and an emergency (reserve) installation. If, however, the main installation complies with all the requirements of an emergency (reserve) installation the latter is not then obligatory.
6. The main and emergency (reserve) installations must be capable of transmitting and receiving on the frequencies (wave lengths) and types of waves assigned by the International Radiotelegraph Convention in force for the purpose of distress and safety of navigation to ships compulsorily fitted with radiotelegraph installations in accordance with the present Convention.
7. The main and emergency (reserve) transmitters shall have a note frequency of at least 100.
8. The main transmitter shall have a normal range of 100 nautical miles, that is to say, it must be capable of transmitting clearly perceptible signals from ship to ship over a range of at least 100 nautical miles by day under normal conditions and circumstances, the receiver being assumed to be one employing a rectifier of the crystal type without amplification.*
9. Sufficient power must be available in a ship station at all times to operate the main radiotelegraph installation efficiently under normal conditions over the above range.
10. All parts of the emergency (reserve) installation shall be placed in the upper part of the ship in a position of the greatest possible safety, as high above the deepest load water line as practicable. The emergency (reserve) installation must be provided with a source of energy independent of the propelling power of the ship and of the main electricity system and must be capable of being put into operation rapidly and of working for at least six continuous hours. For the emergency (reserve) installation, the normal range as defined in paragraph 8 above must be at least 80 nautical miles for ships required to maintain a continuous watch and at least 50 nautical miles for all other ships.*

• Unless a more precise and practical method is available to determine the range of transmitters it is recommended that, as a guide, the following relations between the range in nautical miles (from ship to ship under normal conditions in daytime) and the power of the ship transmitter in metre ampères for 500 kilocycles per second (600 m) be used:—

  100 nautical miles 60 M A
  80 nautical miles 45 M A
  50 nautical miles 25 M A

M being the actual height in metres of the aerial from its highest point to the load line.
A being the current in ampères measured at the base of the aerial in case of B, or fully modulated A2, transmitters.