All physical copies are missing page 3 in this thesis. - McMaster Digitization Center / A computer simulation model was developed to simulate the receiving of raw materials at a dock for an integrated steel plant on the North shore of Lake Erie. The model was formulated to study queue build-up, berth waiting time and the effect of various unloading conditions on dock efficiency. A financial analysis, using present value techniques, was then applied to the model results in order to recommend an optimum berth staging plan under various economic conditions. Historical data on raw material receiving at Hilton Works, Hamilton, were collected and used to develop mathematical functions to describe the random nature of vessel arrivals and berth times. It was determined from this data that vessel arrivals are described by a Poisson distribution and berth times are described by an Erlang distribution. The computer model simulates the dock operation by generating random numbers according to these distributions (Monte Carlo Simulation.) Coal and ore vessel arrivals are merged and respective service times generated. Interferences occur and queues grow and diminish as the facility is simulated through the shipping seasons throughout its expected life. Various unloading rates and vessel tonnages are simulated for a single and double berth operation and the associated waiting times and queue lengths are recorded for each alternative. An economic analysis is performed on the alternatives using present value techniques. The economic analysis indicated that the optimum time to expand the dock to a double berth occurs at a tonnage level of 15 million (coal + ore). To reach this level unloading rates of 10,000 TPH for ore and 8,000 TPH for coal would have to be achieved with an average vessel tonnage of 39,000 metric tonnes. Reducing the unloading rates or average vessel tonnage would move forward the required construction of a double berth and would increase the present value for that alternative. This expansion date will also depend on future economic factors such as cost of capital and escalation rate. The other important conclusion drawn from the economic analysis was that the receiving facility should be expanded in minimum feasible increments because of uncertain economic conditions. This concept dictates that conveyors be installed at minimum capacity, i.e. -belt width and drive size, to handle the first stage tonnage only with provision in the equipment to increase capacity by replacing narrow belts with wider ones and adding additional drive units. The timing for the stages is predicted on several factors, such as: life of the initial belt, tonnage forecast, ship delay costs, and most importantly future economic conditions. For example, it would be advantageous to increase the unloading capacity with a wider belt at the time the initial belt is worn out. Belt and drive staging will take place before the expansion to a second berth in order to defer the capital investment as long as possible. The conveyor system for the second berth can be similarily staged. The study indicated that a good planning strategy would be to initially install a 1.8 m wide belt on 2.0 m wide machinery with 3-1,000 H.P. drives. This system would unload ore at approximately 7,000 t/hr. and coal at approximately 5,000 t/hr. This capability could be increased to 10,000 t/hr. for ore and approximately 8,000 t/hr: for coal by adding a 2.0 m wide belt and 1 -1,000 H.P. drive unit. These rates would be compatible with the expected unloading rates of the future fleet. The decision to increase capacity should be considered when the initial belt is worn out or when delay costs and future economics dictate expansion before that time. The study also indicated that it is poor strategy to design the second berth/conveyor system to be restricted to coal receiving only. The Computer simulation indicated ship delay time for the restricted berth to be approximately three times that for a system with capability to receive ore and coal equally at both berths on either conveyor and either stacker. It indicates that ore receiving is the most important capability and should not be restricted. Even though ore pellets unload more quickly the ore tonnage required is twice that for coal. Therefore, it is recommended to design a completely flexible system . with full provision for expansion to higher unloading rates and larger vessels (850 ft.) and with provision to unload equally from either berth to either conveyor and to have the ability to transfer material between converyors at the head end of the stacker conveyor. / Thesis / Master of Engineering (MEngr)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/23812 |
| Date | 09 1900 |
| Creators | Fulton, Robert |
| Contributors | Smith, A. A., Civil Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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