5.—(1) Subject to sub-paragraph (2), where dangerous goods are being carried in tanks a telephone number where specialist advice concerning the dangerous goods in question can be obtained in English at any time during carriage shall be displayed—
(a)at the rear of the transport unit; and
(b)on both sides of—
(i)any tank;
(ii)the frame of any tank; or
(iii)the transport unit; and
(c)in the immediate vicinity of the orange-coloured plate displaying the EACs,
and shall be in black digits of not less than 30mm in height against an orange-coloured background.
(2) The telephone number may be substituted by the phrase “consult local depot” or “contact local depot” provided that—
(a)the name of the carrier is clearly identifiable from the marking on any tank or the transport unit;
(b)the chief fire officer (as regards England and Wales) or the firemaster (as regards Scotland) of each area through which the transport unit will carry the dangerous goods has been notified in writing of the address and telephone number of the relevant local depot; and
(c)each fire officer or firemaster, as referred to in paragraph (b), has indicated in writing that he is satisfied with the arrangements.