Friction loss testa were carried out on a 287mm I.D. cement mortar lined pipeline. The test length was 81 m. consisting of 9 x 9m lengths of flanged pipe, preceded by a 36 m long approach section. The steel pipes were centrifugally lined. The results showed that over the range of Reynolds numberts from 4.7 x 10 to the fourth to 8.1 x 10 to the fifth achieved during the tests, Darcy friction factors for the pipe followed the Colebrook-White transition function with a roughness k of .01 mm.