LIFT BRIDGE OVER THE MURRAY AT SWAN HILL. XCI. 
2. The absence of masted vessels doing away with the necessity 
of an uninterrupted headway, as afforded by a swing span or 
bascule. : 
3. Narrowness of “low rivers” rendering pivot pier in centre 
of stream objectionable. 
4. The necessity of providing the maximum headway in the 
highest floods. 
5. The low lying land on either side of river necessitating long 
approaches to a fixed bridge with the required headway. 
6. Heavy wool teams on a narrow bridge making long graded 
side spans inadmissible. 
The first two lift bridges in the Colony were erected in 1880 at 
Bourke and Balranald, on a design by Mr. J. H. Daniels, Assis- 
tant Engineer, acting under the late Mr. W.C. Bennett, M. Iust. C.E., 
Commissioner and Engineer-in-Chief for Roads and Bridges, and 
in 1885 the author acting for Mr. J. A. McDonald. M. Inst. C.E., 
Engineer for Bridges, then absent in England on leave, designed 
under the late Mr. W. C. Bennett, the lift bridge over the 
Barwon River at Brewarrina, erected by day labour under the 
Supervision of the late Mr. John Coleman, Resident Engineer 
at Bourke, at a total cost of £7,700. The bridge consists of a 
steel lift span on iron cylinder piers, giving a clear fairway of 47’ 
6” with timber side spans, making a total length of 267’ between 
centres of abutments, the clear headway provided when lift is 
raised to its full height being 223’ above highest flood. 
The two steel main girders of lift span are of light construction, 
the booms being each formed of two angle bars back to back 
riveted to 9” x 3” boom plates, the web being formed of diagonal 
channel struts and flat diagonal bars, the steel web plate cross 
girders 1’ 6” deep pitched 4’ 6” apart, are riveted to bottom flange 
of main girders, whilst steel web plate frames are placed between 
the cross girders to shorten the span of the 3” sawn planking 
forming the floor of bridge. A lateral system of diagonal tie rods 
is secured to bottom booms of main girders which materially 
“ stiffens ” the lift span when being raised or lowered. 
