scope:

This handbook presents compressive strength properties for drydocking timbers and built-up blocks, stability characteristics of high blocks, and friction coefficients for cribbing materials. These values are the result of a series of tests performed under the direction of the Naval Sea Systems Command and are intended to supplement the strength properties of clear wood specimens found in wood handbooks. The timbers used in this study were full-size white and red oak and Douglas fir and consisted of both new (unused) and in-service drydock timber. Because of the variations in strength properties of docking timbers as determined in this study, meaningful engineering calculations on hull block loading need to be conservatively based on the low end of the ranges presented for strength properties.

The purpose of this handbook is to establish the expected degree of performance for typical drydocking timbers and built-up blocks based upon full-scale testing results of new and used docking materials.