Knowledge (XXG)

Double heading

Source đź“ť

313: 362:
the train, while the original 'train' engine would remain at the front of the formation (the reverse of normal practice). This was not universal practice on the GWR, with the company's regulations containing a complicated set of orders to determine whether an assistant engine should be placed inside or ahead of the train engine. These depended on the relative size and power of the two engines in question (larger assistant engines always went in front of the train engine), the
130: 296:, which were often not powerful enough to haul the trains alone. Several accidents on the Midland system were indirectly caused by this 'small engine policy' and the resulting reliance on double-heading. Some were caused by trains stalling despite being double-headed, while others were caused by excessive light-engine movements as locomotives that had been used for double-heading returned to their depots (the 168: 33: 142: 381:
The GWR implemented these unusual restrictions to avoid having smaller, lower-power engines (especially tank engines) without leading bogies being propelled from behind by faster, more powerful engines since this was determined to be a major factor in a fatal and especially destructive derailment at
361:
often maintained a unique practice when double-heading was required, whereby if an extra locomotive was to be added to the front of a train for a particular section of line the second 'pilot' engine (called an 'assistant engine' in official GWR terminology) would be coupled "inside", or directly to
386:
in October 1904. Putting the smaller assisting engine between the more powerful one and the train was deemed to provide better stability at speed and under power for the assisting engine. Despite requiring time-consuming shunting operations each time an engine had to be added to or removed from a
258:
In the days when most trains were locomotive-hauled, double heading was frequently used to return engines to their home depot, or to another point on the railway network, by attaching them to a scheduled train. "Light engine" movements, with no train attached, are avoided where possible as it is
287:
in the northern US was able to switch from triple-headed steam locomotives to a single electric locomotive. The costs of running extra steam locomotives were eliminated, and average train speeds increased because it was no longer necessary to attach and detach the locomotives. In Britain, the
227:
More rarely, certain companies have used double-heading to guarantee a service when they have been aware of the poor quality of their locomotives, on the understanding that if one engine failed in service, the other would suffice to get the train to its
231:
Double heading is a useful practice on single lines even in the absence of a need for more power, as to double-head a train saves making a separate path for a spare engine; it can be repositioned using the traffic path occupied by the service
235:
As double heading has become increasingly uncommon railway companies may advertise specially double-headed services as an attraction to enthusiasts; this occurs regularly but infrequently on the British mainline, whilst the
259:
difficult to find space in the timetable for them. This is exacerbated by the fact that light engines must run at reduced speed because they do not benefit from the braking power or stabilising effect of a following train.
199:, each operated individually by its own crew. The practice of triple-heading involves the use of three locomotives. The practice of multi-heading involves the use of multiple locomotives and so on. 202:
Double heading is most common with steam locomotives, but is also practised with diesel locomotives. It is not strictly the same practice as two or more diesel or electric locomotives working '
374:
should always be coupled inside (i.e. between the other locomotive and its train) of tender engines, regardless of which was the train engine and which was the assistant, while the company's
370:
or not and whether the line being worked was a single upward gradient or contained any level sections or falling gradients. For instance, the GWR required that tank engines without
279:
The risks of double heading as well as its costs (fuel and maintenance costs for the engines, wages for their crews) have led railroads to seek alternative solutions.
221:
The need for additional motive power when a single locomotive is unable to haul the train due to uphill grades, excessive train weight, or a combination of the two.
301: 268:
Double heading requires careful cooperation between the engine crews, and is a skilled technique, otherwise one locomotive's wheels could
237: 224:
Double heading is also used on passenger trains when one locomotive could suffice but would not be fast enough to maintain the schedule.
442: 255:, Cumbria). For security and safety reasons, trains carrying nuclear waste cannot be allowed to be left standing after a breakdown. 206:' (or 'multiple-working'), where both (or all) locomotives are controlled by a single driver in the cab of the leading locomotive. 116: 50: 280: 97: 54: 69: 218:
In the UK it was usually to gain traction on steep inclines, twice the amount of driven wheels – twice the amount of grip.
331:
When a train formation includes two locomotives double-heading the service, they are commonly distinguished by the terms
325: 312: 240:
in England advertises an annual day when all of its passenger trains are double-headed all day, both steam and diesel.
203: 76: 43: 297: 422:
Railway and Locomotive Engineering. A Practical Journal of Motive Power, Rolling Stock and Appliances. Volume 12
83: 244: 321: 65: 354: 341:
for the second locomotive. This should not be confused with the totally different procedure of adding a
269: 184: 400: 304:, this practice was stopped because it was uneconomical, and more powerful locomotives were built. 153: 133:
When double-heading a train, two locomotives are used at the same end—historically with separate
317: 363: 157: 90: 367: 289: 172: 149: 358: 342: 284: 436: 248: 146: 167: 129: 388: 371: 337: 420: 293: 32: 273: 252: 192: 17: 387:
train under these rules, they remained in place on parts of the GWR until
141: 383: 345:
to the rear of a train to assist up a hill or away from a heavy start.
161: 292:
used to use double-heading often, because it built only small, light
375: 311: 196: 166: 140: 128: 176: 134: 26: 366:
of the two engines, whether the engines in question were
243:
In the United Kingdom, double-heading is used to provide
425:. New York: Angus Sinclair Company. 1899. p. 104. 214:
Double heading is practised for a number of reasons:
320:' Wooton and Freshwater running around the train at 57:. Unsourced material may be challenged and removed. 300:in 1910). When the Midland was absorbed into the 272:, which could stall the train or even cause a 8: 117:Learn how and when to remove this message 412: 238:Romney, Hythe & Dymchurch Railway 7: 302:London, Midland and Scottish Railway 55:adding citations to reliable sources 25: 283:has been used in many cases. The 335:for the leading locomotive, and 31: 42:needs additional citations for 1: 326:Isle of Wight Steam Railway 459: 378:tank engines could lead. 443:Rail transport operations 298:Hawes Junction rail crash 191:indicates the use of two 322:Wootton railway station 247:for all trains hauling 328: 180: 171:A double headed steam 164: 138: 355:Great Western Railway 315: 170: 144: 132: 318:A1 and A1X 'Terriers 251:(usually to or from 185:railroad terminology 51:improve this article 353:For many years the 308:Special terminology 154:Dale Creek Crossing 329: 195:at the front of a 181: 165: 139: 364:wheel arrangement 127: 126: 119: 101: 16:(Redirected from 450: 427: 426: 417: 368:tank locomotives 179:, September 2006 160:in southeastern 152:of the 1860s at 145:A double headed 122: 115: 111: 108: 102: 100: 66:"Double heading" 59: 35: 27: 21: 458: 457: 453: 452: 451: 449: 448: 447: 433: 432: 431: 430: 419: 418: 414: 409: 401:Push–pull train 397: 389:nationalisation 351: 316:Double heading 310: 290:Midland Railway 281:Electrification 266: 212: 173:excursion train 150:passenger train 123: 112: 106: 103: 60: 58: 48: 36: 23: 22: 15: 12: 11: 5: 456: 454: 446: 445: 435: 434: 429: 428: 411: 410: 408: 405: 404: 403: 396: 393: 372:leading bogies 359:United Kingdom 350: 349:Configurations 347: 343:banking engine 309: 306: 285:Milwaukee Road 265: 262: 261: 260: 256: 249:nuclear flasks 241: 233: 229: 225: 222: 219: 211: 208: 189:double heading 125: 124: 39: 37: 30: 24: 18:Double-heading 14: 13: 10: 9: 6: 4: 3: 2: 455: 444: 441: 440: 438: 424: 423: 416: 413: 406: 402: 399: 398: 394: 392: 390: 385: 379: 377: 373: 369: 365: 360: 357:(GWR) of the 356: 348: 346: 344: 340: 339: 334: 327: 323: 319: 314: 307: 305: 303: 299: 295: 291: 286: 282: 277: 275: 271: 264:Disadvantages 263: 257: 254: 250: 246: 242: 239: 234: 230: 226: 223: 220: 217: 216: 215: 209: 207: 205: 200: 198: 194: 190: 186: 178: 174: 169: 163: 159: 155: 151: 148: 143: 136: 131: 121: 118: 110: 99: 96: 92: 89: 85: 82: 78: 75: 71: 68: â€“  67: 63: 62:Find sources: 56: 52: 46: 45: 40:This article 38: 34: 29: 28: 19: 421: 415: 380: 352: 338:train engine 336: 333:pilot engine 332: 330: 278: 267: 228:destination. 213: 201: 188: 182: 113: 107:October 2022 104: 94: 87: 80: 73: 61: 49:Please help 44:verification 41: 294:locomotives 204:in multiple 193:locomotives 407:References 274:derailment 253:Sellafield 245:redundancy 210:Advantages 77:newspapers 391:in 1948. 437:Category 395:See also 384:Loughor 162:Wyoming 158:Sherman 91:scholar 232:train. 93:  86:  79:  72:  64:  376:2-6-2 197:train 156:near 135:crews 98:JSTOR 84:books 270:slip 177:Iowa 147:U.S. 70:news 183:In 175:in 53:by 439:: 324:, 276:. 187:, 137:. 120:) 114:( 109:) 105:( 95:· 88:· 81:· 74:· 47:. 20:)

Index

Double-heading

verification
improve this article
adding citations to reliable sources
"Double heading"
news
newspapers
books
scholar
JSTOR
Learn how and when to remove this message

crews

U.S.
passenger train
Dale Creek Crossing
Sherman
Wyoming

excursion train
Iowa
railroad terminology
locomotives
train
in multiple
Romney, Hythe & Dymchurch Railway
redundancy
nuclear flasks

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.

↑