Merry Go Round ============== Introduction ------------ The simulation is in two parts: you must first load (or supervise the loading of) a special inter-regional merry-go-round coal train at Bentley Colliery (just north of Doncaster), and then drive the train on the first stage of its journey up the East Coast mainline to Peterborough where you hand over to a new crew in the West Yard. With over 1,500 tons in tow behind a modern Class 56 or 58 locomotive this is no high speed dash, but more the routine tedium of one of British Rail's heavy freight bread-winners hard at work. Loading At The Colliery ----------------------- Because of assumed limited siding capacity at Bentley, the train of 34 HAA hoppers has to be filled in two passes under the loading bunkers. The locomotive is on automatic slow speed control throughout, moving under the bunkers at a constant speed of 0.5mph. The loading controls and procedure are summarised in the diagram below, and at any stage in the operation you may opt out of manual loading and hand control back to the computer. Hoppers are weighed on a weighbridge as they leave the loading facility, and at the end of the loading stage you will be given a rating of your performance as a bunker operator. [ Figure 1: The Loading Operation ] Optimum load of 32.5 tons per hopper is achieved with hoppers full to rim load line. Overloading as well as under-filling will be penalised. Fine fill rate controlled by the X,Z keys. Coarse fill rate controlled by <,> keys (BBC) or N,M keys (Spectrum). Bunkers refilled when low by pressing RETURN on BBC or ENTER on Spectrum. To hand over control to the computer, press the ESCAPE key (BBC) or Q key (Spectrum). The Drive To Peterborough ------------------------- The Route And Speed Restrictions -------------------------------- An itinerary of your route is given in the form of a gradient profile in Figure 2, and during your run details of your location and other information a driver would have from visual observations and his background knowledge of the route are presented in the form of a continuously updated television display. On leaving the colliery yard at Bentley there is a short but undulating spur to the junction just north of Doncaster where you join the ECML for your journey south. After threading through the Doncaster complex, the line is predominantly double track through the Vale of Trent to Grantham, and in order to clear the path for 125mph Kings Cross bound High Speed Trains you may well be signalled into one or more of the loops at Ranskill, Gamston, Carlton or Claypole. Depending on traffic conditions, you could be diverted onto the relief line for the climb from Grantham to Stoke summit, but in any event are scheduled to run on the up slow line of the quadruple track formation from Stoke to Peterborough. Because of uncertainties in pathing, there is no fixed schedule, but you might expect to arrive at your final destination of Peterborough West Yard after a journey time of around two hours 15 minutes. With your heavily-laden train, all speed limits must be scrupulously observed. The colliery branch has a permanent restriction of 15mph, reflecting the poor condition of the trackwork and the risk of subsidence, but once on the ECML it is generally the 45mph limit of the HAA hoppers rather than the line speed which sets your maximum permissible speed. Where there are exceptions to this you will be given advance notification of the reduction in line speed, this warning commencing 1.5 miles before any permanent way engineering work on the track (pws), 0.5 mile before the two sections of the slow line down Stoke bank with a restriction of 40mph, and where appropriate in signal sequences before being turned into a loop or the West Yard at Peterborough. With the four aspect colour light signals of the ECML an approach signal sequence will consist of a signal at double yellow, a signal at yellow, and then the loop control signal turning from red to yellow (with an appropriate indication as you approach. [ Figure 2: The ECML Between Doncaster And Peterborough ] Motive Power ------------ The Class 56 locomotives were built between 1976 and 1984, the first 30 locomotives by Electropute in Romania and the remainder by BREL at Doncaster and Crewe works. Derived from the Class 47 mixed traffic design, the locomotives are powered by a Ruston Paxman 16RK3CT diesel engine rated at 3250 bhp and for almost a decade have been the principal BR heavy freight locomotives. The Class 58 locomotives, introduced at the end of 1982, are designed to a similar specification as the Class 56s, but are of a much simpler modular unit construction than their monocoque-bodied predecessors. Powered by a Ruston Paxman 12RK3ACT engine of 3300 bhp, the locomotives are the most powerful diesel-electrics in current service on British Rail. Locomotive Controls And Driving Technique ----------------------------------------- Details of your locomotive condition are given in the roster notices before the start of your journey, and as you proceed information about the locomotive controls and performance is given in the lower half of the television display. Engine power is governed by a master controller, which in the simulation is graduated in six notches from 0 (engine idling and drive disconnected) to 5 (full throttle). Current is supplied to the three traction motors on each bogie from a main alternator coupled to the engine crankshank, and notching up is relatively straightforward in that a current limit system comes into operation if too high an engine setting is selected at low speed. Application of too much power will however increase the probability of wheelslip, particularly when starting on adverse gradients with poor rail adhesion. Slippage is detected by the control system and brings an automatic reduction of the applied tractive effort, the severity and duration of which can be reduced by applying sand. If wheelslip is prolonged, you should try notching the controller down a setting, and care should be taken not to drop sand unnecessarily as this will be penalised in the end of game assessment. Once on the move you will find your train much more sluggish to respond that with our express passenger simulations, and this puts a premium on skilful driving. The brake handle also has six settings from 0 (off) to 5 (full emergency application). With a heavy train of loose coal, you should brake with extreme caution, and with multiple aspect signalling and signal distances of typically 0.7 mile on the ECML it should not be necessary to use more than the first couple of brake notches. As you approach all signals at caution or danger you will receive an AWS (Automatic Warning System) indication on the control panel triggered by track-mounted magnets, and this must be cancelled within six seconds or else there will be an automatic application of the emergency brake. If a signal remains at red as you approach you should bring your train to a halt within 35 yards of it in order to obtain telephone instructions from control about the situation. Similarly at the end of the simulation you should draw up within 35 yards of the starting signal in Peterborough West Yard ready for handing over to your relief crew. Game Controls ------------- The computer keys used for the locomotive controls are: Controller: increase > (BBC) or P (Spectrum) decrease: < (BBC) or O (Spectrum) Brakes: increase X decrease Z AWS Cancel: Space Bar Sand: apply by holding down S key Horn: available on the BBC only by pressing the SHIFT key (a short press for a starting acknowledgement and a longer press for a two tone warning) If you want a break during the run, the simulation can be suspended by pressing the H key (for hold), with action restarted by pressing the R key. Loading ------- CHAIN"" Note that users with disc or Econet interfaces should first return to the cassette filing system by typing *TAPE and PAGE=&E00. Bibliography For Further Reading -------------------------------- Modern Railways Pictorial Profile: 5 Class 56s and Class 58s, Harris and Marsden, Publ. Ian Allan Merry-go-rounds: Efficient Movement of Coal, Article by Abbott in September 1983 issue of Modern Railways