876 REPORT—1885. 
platform. Extending between and beyond these, but at right angles, will 
be the other girders required to complete the rectangular platform already 
referred to. The principal work above this will be executed from this 
platform as it is being raised towards the top of the pier. In that work 
will be included the 12-foot rising or supporting columns, the eight-foot 
diagonal columns, and the bracing in the sloping planes. The vertical 
planes will be built similarly as the platform is raised upwards. When 
allis ready to be raised for the first time, the positions of the various 
members in the pier will be somewhat as follows. The four rising 12-foot 
columns will have the whole of their channels and eight of the ten plates 
in section, in each column, at a convenient working height above the 
platform. The other two plates require to be kept off at this point, to 
allow the main lifting girders to pass through the columns, and can only 
be placed in final position from underneath the main lifting girders. The 
columns will only be bolted together at this point, but as few more bolts 
will be required than those necessary to make good work when riveting 
up, very little labour will be lost. The eight-foot diagonal tubes in the 
sloping planes will also be carried up above the level of the platform. 
They pass between the girders, and lie in the sloping planes, and will be 
wholly riveted up above the level of the platform. The bracing in the 
vertical planes, being 12 feet wide, allows the main lifting girders to pass 
through it, and will be built to a large extent from a platform on the top 
of these girders, only the top and bottom bracing requiring to be placed and 
riveted in position underneath the main lifting girders, while the whole of the 
tubes will be built in single pieces. In the case of the bracing girders it is 
intended to take up and fix in position sections of a size convenient for 
handling with despatch under the somewhat novel circumstances around. 
The riveting machines employed will be of various forms, the common 
type being used for such work as the bracing girders, while those for 
the rising and horizontal columns will be the same in principle as those 
riveters employed for the bedplates, with several special features to suit 
the different kind of work. The girders on which the cylinders slide will 
be similar, and similarly placed in relation to the work to be done, one 
being outside the column and the other inside, while at the ends they are 
secured to and made to slide round two circular rings by a small hydraulic 
cylinder. Stiffening packings or struts are placed between these cir- 
cular rings and the channels of the columns inside and plates outside, to 
keep all in true furm, and these are transferred from one point to another 
as the girders pass the various positions at which they are placed. 
The girders are thus made to move round the complete circle, and as 
the hydraulic cylinders on these slide a length of 16 feet, it follows that 
the riveting done at each shifting of the machine is equal to this length 
of the completed column. To enable the riveting to be executed with the 
longitudinal built up channels complete, the power of the hydraulic 
cylinder on the inner girder is transmitted to the rivet through a lever of 
the third order, this cylinder having the amount of greater area necessary 
to exert nearly the same pressure as the cylinder on the outer girder. It 
1s proposed that the whole machine be fixed to the platform and under- 
neath it. It will consequently be raised with it, but during the stationary 
periods between the lifts, it will rivet up the 12-foot rising columns close 
to but always underneath the main lifting girders. Each machine is made 
to carry its own working platform, from which all the necessary operations 
will be conducted. 
