Temporary works are mostly designed by the contractor, but the resident engineer will need to review the design because of the safety responsibility also held by the engineer (see Sections 10.2 and 10.3). On a large project the temporary works may comprise major structures such as caissons, cofferdams, river diversion works, sheet piling, access bridges, etc. Designs for such structures will normally have to be forwarded to the engineer for his consent, though the resident engineer should apply his site checks first so that he can draw the engineers attention to any matters of doubt seen on site.