He returned to England in 1906, taking on a role inspecting locomotives built for the New South Wales Government Railways by British manufacturers.

The design was deployed in many regions throughout Africa, South America, South-east Asia, Australia and New Zealand.

Garratt locomotives were particularly effective on narrow gauge railway lines not only because of their flexibility: the size of their fireboxes below the "bridge" between the two engine units was constrained only by the lateral distance between the bridge frames – much greater than the distance between the narrow frames of non-articulated locomotives.

[note 1] This greatly increased the capacity to generate steam, on which power output depended.

High efficiency compared with that of fixed-frame locomotives reduced the numbers of locomotives per train, allowed much heavier trains, and averted the need to convert rail lines to a wider gauge – an incentive for further rail network and economic expansion.