Is written instruction a condition precedent?

Russell v. Viscount Sa da Bandeira (1862) 143 ER 59

Rusell, a London based shipbuilder was contracted to construct a warship by the Portuguese government. Also, the government employed Admiral Sir. George Rose Sartorius to oversee the work. The scope of work was very general (e.g. it use the words 'as usually supplied', 'in a manner similar to' father providing specific details)

Contracts provide that the contractor is not entitled to get paid for extra work/variations unless those were instructed in writing by the Admiral.

The issue was whether the contractor is entitled to get paid for extra work/variations, as they were not instructed in writing by the Admiral.

Court held:

* The clause was clear and shall give full effect

* “….(contractor) might have declined to comply with these requests unless they were made in written”