78 IMPROVED FISHERY HARBOUR ACCOMMODATION 



of wood is thus formed to exclude the violence of the 

 waves. An iron hasp or other means are used to keep the 

 logs from rising. They are quite effective as long as they 

 stand, and the longest mentioned by Mr. Stevenson are 

 about 45 feet. At Hartlepool and Seaham they are 

 worked by aid of steam power. At Hynish Harbour, 

 Argyllshire, where logs of 20 feet long and 12 inches 

 square were used between the supports, at a small tide 

 basin, Mr. Stevenson states they were frequently broken 

 by the violence of the waves. Seven were broken within 

 six years at different dates. They were perfectly sound, 

 and would stand a pressure of 30 tons. Although 

 perfectly effectual, these booms are unsuited where there 

 is much traffic, shipping and unshipping so many logs 

 involving delay which might result in serious conse- 

 quences. 



They are not used except under storm emergencies, but 

 could not be recommended for fishing harbours used by a 

 number of boats, as it would be a most serious matter for 

 one or more boats to arrive and find the entrance closed. 

 Signals, of course, are in use to warn vessels off, but might 

 be perceived too late to enable approaching craft to clear 

 the land. There is one instance of the use of a boom at a 

 harbour in the south of Cornwall, but it is a clay-loading 

 and not a fishing harbour. 



Mr. Stevenson suggests for large spaces tubular booms 

 of boiler plate, pervious to water, so that they would sink 

 of their own gravity, and not require to be warped down 

 like logs of wood. 



Storm-gates have also been used in these positions, 

 with more or less success, to close the entrance. 



