APPENDIX L— Continued.

69

VI. ERECTION. 169. The contractor will be required to erect the superstructure complete

in every respect including riveting.

170. Everything is to be completed ready to receive the timber floor.

157. The contractor will be expected to receive all material as it arrives 171. The erection shall include the placing and riveting of the iron hand rail,

on the cars, to unload this material and store it in a material yard until ready .0' 172. The contractor will be expected to raise the ties for the central span

for erection.

158. He will be held responsible for the custody and care of all super-structure material after its arrival.

159. The material of the main Continuous Superstructure will be deliveredon cars on the east side of the river.

160. When ready for erection, the Bridge Company will switch any cars onwhich this material has been loaded, to a point where it can be transferred tobarges, no charge being made for such switching.

161. All material for the Deck Span at the west end will be delivered oncars on the west side of the river.

162. A track will be laid to a convenient position for unloading material,near Pier Y, and no switching will be done after the material has once beenunloaded.

163. The contractor will be required to keep all the material in good con-dition, and in case of its becoming dirty or rusty, will be expected to clean itbefore erecting.

164. The contractor will be required to paint all surfaces which will beinaccessible for painting after erection, the paint being furnished by the BridgeCompan 3 r .

165. The contractor will be required to furnish all tools, barges and falsework of every description, excepting power riveters.

166. The contractor will be required to remove all work which he may putin the river so that there will be nothing left either to interfere with navigationor to catch drift.

167. No holes shall be drilled or bolts placed in the piers without theexpress permission of the engineer.

168. All bolts so put in shall be removed and the holes carefully filledwith Portland cement mortar, and any damages done shall be charged to thecontractor.

and the adjoining cantilever arms and distribute them without charge. Thisdoes not include any framing, fitting or bolting. The ties will be delivered tothe contractor loaded on barges.

173. The central span will be raised on false work.

174. The west intermediate span will be raised on false work.

175. The east intermediate span may be raised on false work, or without,at the option of the contractor.

176. The anchorage arm east of Pier I will be raised on false work.

177. The three projecting cantilever arms will be built out without falsework.

178. It is expected that the anchorage arm and the cantilever arms project-ing from Pier I can be raised in the fall of 1890. That the deck span at thewest end can be raised in the following winter. That the false work for thecentral span can be put in in August and September of 1891, and the erectionof this span completed in the following month. That the cantilevers can bebuilt out and the entire bridge completed by January 1, 1892.

179. All erection shall be done under the direction of the Chief Engineerand in conformity with his requirements.

180. The wall-plate castings shall be set on Piers II and III before thebottom chord is placed.

181. The expansion rollers and the bolster complete shall be set on PierIII. The bottom chords shall then be put together and riveted up complete.The expansion end shall then be adjusted so that the axis of the rollers will beexactly vertical at a temperature of 70 degrees Fahrenheit. This adjustmentshall be made at a time when there has been no sun on the steel work for tencontinuous hours, and when there has been no sudden change of temperature.The span shall be erected complete and the end rollers shall be examinedagain, and if any error is found, shall be corrected, the correction being madeunder the same conditions as to sunshine and sudden changes of temperature

as the original adjustment. Special care shall be taken with the rollers whilethe span is being swung, and if by any accident they get out of place, thespan shall be wedged again and the rollers be readjusted.

182. The eye bars in the end panel of the top chord shall be stiffened so asC to resist compression by fitting planks between the bars and bolting the whole

together.

183. When the erection of the central span is completed, the two cantileverarms shall be built out and the two intermediate spans erected, thus com-pleting the bridge.

184. All rivets shall be regular in shape with hemispherical heads con-centric with the axis and absolutely tight. Tightening by calking or recuppingwill not be allowed.

185. All riveted joints which have to resist tension, this including all jointsin both chords of the central span and all joints in the bottom chord of theintermediate spans, shall be riveted by power, except in such special cases asthe engineer may authorize hand-driven rivets. This authority will never begiven for rivets in splices of web plates.

186. A power riveter, with air pump or with hydraulic pump and accumu-lator, will be furnished by the Bridge Company. The contractor will berequired to keep the same in repair and will not be relieved from any respon-sibility in this connection, the Bridge Company only agreeing to bear the costof the machine.

187. No extra bills are to be rendered by the contractor, except for newwork not embraced in the contract. Charges for reaming holes, fitting bolts inplace of rivets and other small work of this class will not be allowed.

188. The setting of the wall plate castings, including the drilling of holesin masonry for the anchor bolts, the packing of rust cement or lead under thecastings and all other work connected therewith, is to be done by thecontractor.

189. The contractor will be responsible for any damages which the BridgeCompany may be held liable for in consequence of any of his work.

January Uh, 1890.

GEO. S. MORISON,

Chief Engineer.

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