Present Perfect Passive and Past Simple Passive
Use of passive in order to focus action itself, not on who does the action (the agent).
The Present Perfect passive used to talk about events that happened in a period of time that continued from the past up to the present. Time expression not used with present perfect tense because time is unspecified.
have/has + been + past participle
E.g. The topside has been fitted to the spar
The Past Simple passive used with completed actions or actions that took place at a specific time.
was/were + past participle
E.g. The topside was fitted to the spar in 2009.
For more information, see Course Book Language Summary, page 101
Cohesion; by (means of); (in order) to
Method: to explain how we did something
use ‘by’ …-ing / using / by means of
E.g. The spar was secured by fastening it to the seabed with nine cables.
Purpose: to explain why we did something
in order + infinitive / in order to
E.g. The spar was secured (in order) to prevent it from moving around in heavy seas.