General remarks - Examples of various types of girderwork - Remarks upon the design of riveted connections - Fundamental rules and the study of good examples - The making of rivet-holes - Punching and the punching machine - Burrs, and the holes which they imply - Drilled holes - The templet system - Making and use of templets - Combined punched and drilled or rimered holes - Rivets - Shape and dimensions of rivet-heads - Pan-heads - Cup-heads - Percentage of weight of heads and points - Table of weights of heads and points - Methods of riveting - Hand riveting - Hydraulic riveting - Pneumatic riveting - The pneumatic hand hammer and its applications - Girderwork as applied to bridge construction - Example of viaduct construction - Cast-iron cylinders - Details - Lengths of cylinders - Bottom lengths - Upper lengths and cap - Holding-down bolts of main girders - Cylinder bracing - Main girders - Footway and flooring - Cross girders - Expansion arrangements - Roadway - Details in connection with mixed traffic - Curbing - Girderwork for machine or boiler shops, steel foundries, engine-houses, etc. - Traveller girders - Travelling cranes and their loads - Wheel pressures - Crane wheels - Table of weights of overhead travelling cranes - Analysis of total loads and resulting reactions of supports - Minimum dimensions and clearances for overhead travelling cranes - Headway required - Truth of gauge of road for overhead travelling cranes - Types of girders for roadway - Sections of rails and methods of connection - Roadway at walls of shops - Details - Lattice girderwork for roofing - Example and details of riveted connections - Application of girderwork to the support of cast-iron water-tanks - Consideration of the details of the tanks themselves - General arrangements of such tanks - Bottom and side plates - Subdivision of tanks - Plate flanges - Tie rods - Arrangement of girderwork - Details of roofing arrangements in connection with tanks - Gutters and gangways - Connections of pipe-work, etc. - Table of the weight of mild steel bolts and nuts.

Riveted girderwork in general covers so wide an area of constructive practice, and its application is found in so many different directions, that it is hopeless to deal adequately with the subject in one chapter of such a collection of notes as the present. All that can here be done is to offer to the student some examples of the application of girderwork in one or two particular directions, accompanied by a few remarks on some practical aspects of rivets and rivet-holes.

Nor can the theory of the beam be in any way entered on. The methods of determining bending moments, either by graphic or analytic methods, the theory of shearing forces, and of stresses in triangulated or latticed structures, together with the processes of apportioning the sectional areas of metal required, and of determining the correct lengths of flange-plates, etc., must be assumed to have been acquired in greater or less degree by the reader of these notes.

The same remark must also be taken to apply to what may be called the theory of riveted joints in the application of safe limits of shear and bearing stresses,1

The examples of various types of girderwork which are given in the illustrations which follow are all of comparatively small span, not exceeding 60 feet, as the consideration of girders of very large span does not enter within the limits of these notes.

Thus in Figs. 66 and 73 we have examples of ordinary single-plate web-girders to carry traveller rails, while in Figs. 244 and 245 we have details of a double-webbed or box-girder for the same purpose.

Figs. 116 and 117 show details of single-webbed plate-girders carrying tank-work above, forming a portion of the roof over an engine-house, and it will be convenient to consider, in connection with these girders, such details of the tanks themselves as will be found practically useful to the draughtsman.

In Figs. 33 and 51 are given details of single-web plate-girderwork for bridge construction of the type described, and in Figs. 360 and 361 are found details of box and single-web girders used in jetty construction.

Figs. 82 to 101 show some details of lattice girders for roof construction, especially those details of riveted connections which are all important in these as in other branches of girderwork.

It is somewhat difficult to describe in so many words all the mental processes which attend the design by an experienced draughtsman of a well-thought-out riveted connection, and yet there is no detail associated with the design of structural steelwork which will more reveal the efficiency or otherwise of the designer than this.

1 Among the numerous treatises which have been issued on these subjects the student may profitably consult Part IV. of "Notes on Building Construction," in addition to more advanced works on the same subjects; " Bridge Construction," by Prof. T. Claxton Fidler (Griffin); and as regards riveted joints, Prof. Unwin's "Machine Design" (Longmans).

It is true that all the mechanical elements which form the basis of the design of the connection may be present to his mind - the total stress, the number and area of rivets, the bearing areas, may all have been correctly determined and provided for, but there will often remain a residuum of conditions to be met outside theoretical requirements as to which there may be a right way or a wrong way of procedure. The experienced draughtsman will almost instinctively choose the right way, although he might find a difficulty in explaining in a few words the reasons for his choice.

Oblique connections of all sorts will generally tax the ingenuity of the draughtsman more than those which are square, and if the conditions on one side of the girder or the connection differ in some way from those on the other, it is always desirable to remember both ends of the rivet, and not that end only which is represented on the plane of the paper. There are not wanting in public places evidences of the want of this precaution, which may serve as examples to the junior draughtsman of a wrong method of procedure, of how not to design a riveted connection.