183:. At low speeds, up to 24 mph, the four engines were brought into gear one-by-one. Above this speed, and up to the locomotive's maximum of 84 mph, the supercharger engine speed was controlled by a governor to maintain the supercharged mass-flow and thus maintain the output power as a constant. At full speed, the supercharging effect had been reduced to almost nothing, as the flow through the supercharger was now equivalent to the normal demand of the main engines at this speed. Although this system proved flexible in providing a smooth drive and was reliable in service, it had the drawbacks of complexity and also that the potentially more powerful engines were not working at their maximum when demands on the locomotive were at their maximum.
220:
161:
147:, it is possible to increase the torque (and thus power) at low speeds, so as to match the naturally-aspirated maximum power at the torque peak. If the turbocharger and its inlet manifold are carefully sized to provide the necessary boost at low pressure, but for the volume delivered to stay relatively constant above this, an inverse torque characteristic with rpm can be achieved.
124:
The Hi-Dyne principle was to produce an engine where the torque curve was the inverse of the usual: a maximum at low revolutions and decreasing gradually with increasing speed, so that the overall power (the product of torque and power) would remain constant, whatever the speed. Such an engine cannot
120:
The output power of an engine is the product of its torque and speed. The torque varies with speed, increasing to a peak value and falling away both above and below this. The range for which the torque is a useful proportion of the maximum is described as the 'power band'. Diesel engines generally
104:
One of the main needs for a transmission is to match the speed of the engine to the speed of the locomotive, so that the engine can work in its useful operating speed range. All locomotives need to deliver high torque from zero rail speed for startup. The overall range of gear ratios required from
647:
316:
Paxman was not alone in trying to develop diesel engines which gave high torque at low speed. Italian inventors Enrico Hocke and Fausto
Zarlatti patented a "Diesel type locomotive with direct transmission and with automatically supercharged motor when decreasing the velocity" in 1938, patent
140:, had shown that a robustly constructed diesel engine could be supercharged heavily, such that its output torque could become several times greater. The eventual limitation on this process became the engine's ability to extract power through the work done on the piston by the expanding gases.
174:
The same concept of a constant-power diesel engine by variable supercharging had earlier been used in the multi-engined 2,000 bhp mechanical transmission Fell locomotive (British Rail 10100). This used six engines in total: four Paxman 12RPH power engines and two
271:. This gearbox had the advantage that it avoided the momentary loss of power when changing gear. This was a valuable feature when light locomotives were starting heavy trains on inclines, as it helped to avoid the train running away from control.
289:
and it had been intended to name the locomotive similarly on its delivery. To avoid confusion with the
Hudswell Clarke, and association of this prestige project with such a small and minor locomotive, DP1 instead acquired the name
76:
appeared in the 1930s, after the availability of reliable, compact diesel engines. The first were low-speed shunters with mechanical transmissions. These were followed by more powerful high-speed express locomotives with
191:
The Hi-Dyne used a turbocharger characteristic curve that was adequate to provide full boost at low rpm, but was choked above this as engine speed increased, so that the boost reduced and thus also the output torque.
642:
105:
the transmission thus depends on the maximum speed of the train. The narrower the power band of the engine, the more precise control of gearbox ratio is required, either by using a
263:. The governor was set to give a constant power output of 210 bhp between 735 and 1,250 rpm. The transmission fitted was a three-speed Dual Fluidrive gearbox (a form of
54:
274:
One of the more lasting, although obscure, legacies of this locomotive was due to its name. This locomotive first appeared in 1954, during the construction of
304:
Paxman subsequently supplied sixteen Hi-Dyne engines, based on the 6 cylinder RPHXL (contracts 55096-103 and 55721-8) to
Hudswell Clarke for locomotives for
645:, "Diesel type locomotive with direct transmission and with automatically supercharged motor when decreasing the velocity", published 26 April 1938
219:
346:
The broad design for the Fell locomotive was established by the time of the 1947 agreement to build it. It first ran on the main line in 1951.
333:
Above this, too much of the gas energy remains in the exhaust and cannot be extracted as useful work. One solution was the development of the
456:
409:
160:
667:
176:
106:
672:
626:
101:
had yet been developed. There was a clear demand for a powerful and reliable diesel locomotive, based on a mechanical transmission.
305:
244:
682:
610:
98:
112:
Rather than building increasingly complicated transmissions, Paxman chose instead to develop a more flexible engine.
78:
85:
were expensive and complicated though, often requiring entirely new skills for their maintenance staff. Although
543:
243:
industrial locomotive. This was tested for a range of industrial uses, particularly for colliery traffic on the
298:
264:
121:
have a broader band than petrol engines and they also lose less fuel-efficiency at part throttle settings.
677:
367:
design and later merged with Roots (also of
Connersville) to form the Roots Connersville Blower Company.
360:
334:
279:
133:
448:
401:
364:
275:
228:
200:
86:
203:. Rather than the usual arrangement where a control input from the driver's lever sets an engine
180:
169:
618:
359:, Yorkshire, who manufactured under licence some products of the Connersville Blower Company of
622:
452:
405:
73:
31:
207:
that is maintained by a governor, in the Hi-Dyne engine the control input selected an output
90:
35:
248:
240:
58:
562:
524:
485:
377:
268:
196:
94:
82:
661:
295:
129:
43:
27:
356:
260:
256:
247:. Unusually for the testing of a small locomotive, the test trains also included a
144:
39:
337:, where a power recovery turbine extracts further work from this exhaust.
252:
488:(Report). Davey Paxman & Co. Ltd. I.P. 1000/12/56 Publication 1487.
137:
62:
595:
Chapman, G.W. (1949). "19: Installation of High-speed Oil
Engines".
429:. Vol. II (2nd. June 1956 ed.). Caxton. pp. 227–228.
599:. Vol. I (2nd. June 1956 ed.). Caxton. pp. 188–189.
218:
159:
50:
425:
Chapman, G.W. (1949). "14: Supercharging and Where it Leads".
380:
that were used in many small
British locomotives of the 1950s.
355:
Holmes-Connersville, a joint venture between WC Holmes of
46:
to give a constant power output across their speed range.
445:
Hydraulic vs
Electric: The battle for the BR diesel fleet
398:
Hydraulic vs
Electric: The battle for the BR diesel fleet
125:
be achieved by normally-aspirated engine design alone.
484:
D M Pearce, AMIMechE, Chief
Research Engineer (1956).
179:
A210D engines solely to drive the Holmes-Connersville
235:
In 1954 the first prototype Hi-Dyne was installed in
438:
436:
132:
diesel engines from the 1930s onwards, initially by
109:or a discrete ratio transmission with more ratios.
519:
517:
515:
513:
396:Clough, David N. (2011). "5: Transmission Wars".
443:Clough, David N. (2011). "4: Mechanical drive".
376:The Fluidrive Engineering Co. of Isleworth made
506:. Ruston-Paxman Group: 1. September 1954. No 7.
486:The Paxman "Hi-Dyne" Engine for Diesel Traction
471:General Arrangement drawing, British Railways
211:level, which was maintained by the governor.
8:
580:"Hudswell Clarke Constant H.P. Locomotive".
497:
495:
285:. DP1 already had the internal project name
81:. These electric transmissions and their
479:
477:
388:
326:
615:The Deltic Locomotives of British Rail
49:The name "Hi-Dyne" is a reference to
7:
363:. Connersville refined the original
251:. The engine was a 6-cylinder RPHXL
107:continuously variable transmission
16:British experimental diesel engine
14:
306:Sierra Leone Government Railways
529:Paxman and Diesel Rail Traction
195:Engine fuel supply through the
561:Hugh Llewelyn (October 1972).
1:
597:Modern High-Speed Oil Engines
542:Gordon Edgar (27 June 1970).
427:Modern High-Speed Oil Engines
99:diesel-hydraulic transmission
79:diesel-electric transmissions
69:Diesel-mechanical locomotives
34:by the British engine makers
245:Stockton to Darlington line
26:was a form of experimental
699:
167:
668:Diesel locomotive engines
673:Diesel engine technology
265:dual clutch transmission
582:Diesel Railway Traction
531:. paxmanhistory.org.uk.
563:"Hudswell Clarke D810"
502:"The Hi-Dyne Engine".
232:
165:
683:Paxman diesel engines
544:"Hudswell Enterprise"
504:Colchester Newsletter
361:Connersville, Indiana
335:turbo-compound engine
223:Hudswell Clarke D810
222:
163:
42:. They used variable
584:: 3–9. January 1955.
229:Ashford Steam Centre
199:was controlled by a
93:was in use in light
61:, and implicitly to
619:David & Charles
181:Roots superchargers
164:The Fell locomotive
451:. pp. 36–42.
404:. pp. 50–51.
233:
170:British Rail 10100
166:
74:Diesel locomotives
32:rail transport use
525:"Hi-Dyne Engines"
458:978-0-7110-3550-8
411:978-0-7110-3550-8
267:) with a pair of
116:Hi-Dyne principle
690:
652:
651:
650:
646:
639:
633:
632:
617:. Newton Abbot:
607:
601:
600:
592:
586:
585:
577:
571:
570:
558:
552:
551:
539:
533:
532:
521:
508:
507:
499:
490:
489:
481:
472:
469:
463:
462:
440:
431:
430:
422:
416:
415:
393:
381:
374:
368:
353:
347:
344:
338:
331:
278:, the prototype
97:, no high-power
91:torque converter
698:
697:
693:
692:
691:
689:
688:
687:
658:
657:
656:
655:
648:
641:
640:
636:
629:
609:
608:
604:
594:
593:
589:
579:
578:
574:
560:
559:
555:
541:
540:
536:
523:
522:
511:
501:
500:
493:
483:
482:
475:
470:
466:
459:
442:
441:
434:
424:
423:
419:
412:
395:
394:
390:
385:
384:
378:fluid couplings
375:
371:
354:
350:
345:
341:
332:
328:
323:
314:
312:Similar engines
269:fluid couplings
249:dynamometer car
241:Hudswell Clarke
217:
189:
172:
158:
156:Fell locomotive
153:
128:Experiments in
118:
95:diesel railcars
83:traction motors
71:
17:
12:
11:
5:
696:
694:
686:
685:
680:
675:
670:
660:
659:
654:
653:
634:
627:
602:
587:
572:
553:
534:
509:
491:
473:
464:
457:
432:
417:
410:
387:
386:
383:
382:
369:
348:
339:
325:
324:
322:
319:
313:
310:
255:fitted with a
216:
213:
197:injection pump
188:
185:
168:Main article:
157:
154:
152:
149:
143:By applying a
117:
114:
70:
67:
30:developed for
15:
13:
10:
9:
6:
4:
3:
2:
695:
684:
681:
679:
678:Supercharging
676:
674:
671:
669:
666:
665:
663:
644:
638:
635:
630:
628:0-7153-8110-5
624:
621:. p. 5.
620:
616:
612:
606:
603:
598:
591:
588:
583:
576:
573:
568:
564:
557:
554:
549:
545:
538:
535:
530:
526:
520:
518:
516:
514:
510:
505:
498:
496:
492:
487:
480:
478:
474:
468:
465:
460:
454:
450:
446:
439:
437:
433:
428:
421:
418:
413:
407:
403:
399:
392:
389:
379:
373:
370:
366:
362:
358:
352:
349:
343:
340:
336:
330:
327:
320:
318:
311:
309:
307:
302:
300:
297:
293:
288:
284:
283:
277:
272:
270:
266:
262:
258:
254:
250:
246:
242:
238:
230:
226:
221:
214:
212:
210:
206:
202:
198:
193:
186:
184:
182:
178:
171:
162:
155:
150:
148:
146:
141:
139:
135:
131:
130:supercharging
126:
122:
115:
113:
110:
108:
102:
100:
96:
92:
88:
84:
80:
75:
68:
66:
64:
60:
56:
52:
47:
45:
44:supercharging
41:
37:
33:
29:
28:diesel engine
25:
23:
637:
614:
605:
596:
590:
581:
575:
566:
556:
547:
537:
528:
503:
467:
444:
426:
420:
397:
391:
372:
357:Huddersfield
351:
342:
329:
315:
303:
294:, after its
291:
286:
281:
273:
261:turbocharger
257:Brown Boveri
236:
234:
224:
215:Applications
208:
204:
194:
190:
173:
145:turbocharger
142:
127:
123:
119:
111:
103:
72:
48:
21:
20:
18:
611:Webb, Brian
317:US2115525.
299:prime mover
239:, a 48-ton
19:The Paxman
662:Categories
643:US 2115525
321:References
287:Enterprise
237:Enterprise
225:Enterprise
40:Colchester
449:Ian Allan
402:Ian Allan
280:Class 55
87:Föttinger
613:(1982).
259:VTR 160
253:V engine
201:governor
57:unit of
231:in 1972
187:Hi-Dyne
151:Engines
22:Hi-Dyne
649:
625:
567:Flickr
548:Flickr
455:
408:
296:Deltic
292:DELTIC
282:Deltic
138:Saurer
134:Sulzer
63:torque
36:Paxman
24:engine
365:Roots
209:power
205:speed
59:force
623:ISBN
453:ISBN
406:ISBN
136:and
53:, a
51:dyne
276:DP1
227:at
177:AEC
89:'s
55:CGS
38:of
664::
565:.
546:.
527:.
512:^
494:^
476:^
447:.
435:^
400:.
308:.
301:.
65:.
631:.
569:.
550:.
461:.
414:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
