(e) Subject to the provisions of the next following sub-paragraph, each lamp shall be separately illuminated and the effective diameter of the lens thereof shall be not less than 120 nor more than 130 millimetres.
(f) When the signal is operated, each lamp shall show its intermittent red light at at rate of flashing of not lass than 60 nor more than 90 flashes per minute, and in such a manner that the lights of one of the vertical pairs are always shown when the lights of the other vertical pair are not shown.
(g) The height or the centres or the lenses comprising the lower at the horizontal pairs from the surface of the carriageway in the immediate vicinity shall be in the case of signals placed at the side of the carriageway not less than 1.8 nor more than 3.2 metres and in the case of signals placed over the carriageway not less than 58 nor more than 6.8 metres.
(h) No lettering of any kind shall be used upon any of the lenses.
(4) The size, colour and type of light signals prescribed by this paragraph shall be as follows:—
(a) two lamps each showing an intermittent red light and one lamp showing a steady amber light shall be used;
(b) the lamps showing an intermittent red light shall be arranged horizontally so that there is a distance of not less than 585 not more than 665 millimetres between the centres of the lenses of the lamps;
(c) the lamp showing the amber light shall be placed below the red lenses in such a position that a vertical line passing through the centre or that lamp is horizontally equidistant from the vertical lines passing through the centre of each red lens and that the vertical distance between a horizontal line passing through the centres of the red lenses is not less than 235 nor more than 345 millimetres;
(d) each lamp shall be separately illuminated and the effective diameter of the lens thereof shall be not less than 195 not more than 220 millimetres.
(e) when the lamps showing an intermittent red light are operated, each such lamp shall show a red light at a rate of flashing of not lass than 60 not more than 90 flashes per minute and in such a manner that the light of one lamp is always shown at a time when the light of the other lamp is not shown;
(f) the height of the centre of the amber lens from the surface of the carriageway in the immediate vicinity shall be in the case of signals placed at the side of the carriageway or on a street refuge not less than 6.1 nor more than 4 metres and in the case of signals placed elsewhere and over the carriageway not lass than 6.1 nor more than 9 metres;
(g) the lenses shall be provided with a rectangular backing board having an overall width of not less than 1.3 metres and extending not less than 300 millimetres above the centre of each of the red lenses and not less than 300 millimetres below the centre of the amber lens which board shall be coloured black, save for a white border having a width of not less than 80 not more than 100 millimetres on the side from which the lamps show;
(h) the sequence of the signal lights under this paragraph shown tor the purpose for controlling vehicular traffic shall be amber followed by red,
(i) no lettering of any kind shall appear on any of the lenses.
(5) Light signals prescribed by paragraph (4) may be surmounted by a cross of the size, colour and type shown in diagrams 542 and 542.1.
