A test plant has been constructed for measurements of local heat-transfer coefficients and frictional pressure drops on the shell side of spiral-wound LNG heat exchangers. Measurements have been performed with gas flow, liquid film flow and two-phase shear flow. This paper focuses on the measurements and the results from the gas flow measurements. 221 gas flow heat-transfer measurements and 80 gas flow frictional pressure drop measurements have been performed at a Re-number range of 5000-170 000 with nitrogen, methane, ethane and methane/ethane mixture as test fluids. (C) 2003 Elsevier Ltd. All rights reserved.