Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2021

Summary of significant accounting policies

Property, plant and equipment

Office premises	47 to 51 years
Leasehold improvements	over terms of the leases or the useful lives whichever is less
Furniture, fixtures and office equipment	3 to 5 years
Motor vehicles	4 years
Testing equipment	3 years

Engineering segment backlog

	2021		2020
	US$’000		US$’000
Engineering segment		5,400		11,581