BRIDGING LITTLE WANGANUI RIVER

Hokitika Guardian, 29 April 1921, Page 4

BRIDGING LITTLE WANGANUI RIVER

LOW LEVEL ISIUDGE PROPOSALS

Tho following is the report of Overseer Milln'T <m the question of a low level bridge to afford a suitable crossing for collides at the Little Wanganui river, South Westland: - Sir. I have tho honour, to report having inspected a site and taken levels for the proposed low level bridge crossing. Little Wanganui River. There is on 1 \ one site, seven hundred and fifty links above the line of telephone posts that could he crossed by a bridge to span the present stream. In addition trhliie. would not he possible over the bench approaches to the other bridge sites during a small Hood ol three loot in height above the norma! water level, owing to several small overflow channels which would require to he crossed to reach the crossing if constructed in anv position below the site mentioned.

The construction of a low level bridge over this stream oilers no obstacles during construction, but it must he understood that no guarantee of safetv can he given as the .structure uiav he destroyed or partly so by drift timber (luring the first heavy Hood. The enormous amount ol heavy timber carried l>y the stream which is fairly rapid during high flood, is suit sooner or later to destroy the bridge as no structure on a low level can. especially in this river, withstand the amount of drift that would collect during high Hood. The present proposal is for a three span bridge, each span being 30 feet in length supported on 3 pile piers, each pile shod with 301 b shoes and driven 15 feet below the bottom of the stream; each span is to contain 3-30 by lo x 8 stringers stiffened by filling pieces between each stringer and kept in position by tie rods passing through each stringer- on one side ot filling pieces. Heads of piles will ho blocked also under cap to withstand thrust, decking will be 12 toot h.v 8 x 3; with 8-inch diameter, round undressed wheel guards; piles will ho round totara 11 inches in diameter at heads. 3he height of proposed bridge provides for a live foot rise in the river before the decking is nearly covered by water. A better suggestion than the low level bridge would he to approach the Public Works Department with the view to Inning three permanent spans of the Little Wanganui Traffic bridge constructed without delay. This would pro vide a sale crossing for traffic as it would he available during fairly high flood. In mv estimate for the low level bridge I have provided for first class hewn timber for stringers and sawn decking, the cost of construction and ironwork would he the same for either class of timber, and if good material is used the structure could he dismantled when necessary and used ill oilier work.

In i sibilating the cost of the low level bridge at £3111) I have provided for a, bridge 00 feet in length, and 1 heliiwe if this sum were offered to flic public Works Department they would provide a. permanent structure of sufficient length to allow traffic to cross in safetv and continue the work to completion as funds and labour became a vailable. (Signed) WTTJJAM MTLLNER. The foregoing report has been referred to the Westland Chamber of Commerce. and will he considered at the monthly meeting on Tuesday night next, when a course of action will he decided upon.