CN U-1-a and U-1-b
{{Short description|Canadian locomotive classes (1923–1962)}}
{{Use dmy dates|date=February 2021}}
{{Infobox locomotive
| name = Canadian National U-1-a and U-1-b
| powertype = Steam
| image = CN 6015.jpg
| alt =
| caption = CN U-1-a locomotive 6015; On public display at Jasper, Alberta, since July 1972
| designer =
| builder = Canadian Locomotive Company
| ordernumber =
| serialnumber =
| buildmodel =
| builddate = 1923–1924
| totalproduction = 16 (U-1-a) 21 (U-1-b)
| rebuilder =
| rebuilddate = 1947 (1)
| numberrebuilt = 1 ({{abbr|No.|Number}} 6001)
| whytetype = 4-8-2
| uicclass = 2′D1′ h2
| gauge = {{track gauge|ussg}}
| leadingdiameter = {{convert|34+1/4|in|m|3|abbr=on}}
| driverdiameter = {{convert|73|in|m|3|abbr=on}}
| trailingdiameter = {{convert|43|in|m|3|abbr=on}}
| minimumcurve = 16°
| wheelbase = Loco: {{convert|41|ft|9|in|m|abbr=on}}
| length = {{convert|90|ft|4+1/4|in|m|abbr=on}}
| width = {{convert|10|ft|9+5/8|in|m|abbr=on}}
| height =
| axleload =
| weightondrivers = {{convert|233790|-|235390|lb|t|abbr=in}}
| locoweight = {{convert|355570|-|355570|lb|t|abbr=in}}
| tenderweight =
| locotenderweight = {{convert|602600|-|603870|lb|t|abbr=in}}
| tendertype =
| fueltype = Coal or oil
| fuelcap = {{ubl | Coal: {{convert|17|-|20|LT|abbr=on}} | Oil: {{convert|4000|-|5000|impgal|sigfig=3|abbr=on}}}}
| watercap = {{convert|9500|-|10000|impgal|abbr=on}}
| tendercap =
| sandcap =
| boiler =
| boilerpressure = {{convert|210|lbf/in2|MPa|abbr=on}}
| feedwaterheater =
| firearea = {{convert|66.7|sqft|m2|abbr=on}}
| tubearea =
| fluearea =
| tubesandflues = {{convert|3730|sqft|m2|abbr=on}}
| fireboxarea = {{convert|319|sqft|m2|abbr=on}}
| totalsurface = {{convert|4049|sqft|m2|abbr=on}}
| superheatertype = Schmidt
| superheaterarea = {{convert|810|-|1087|sqft|m2|abbr=on}}
| cylindercount = Two, outside
| cylindersize = {{convert|26|x|30|in|m|abbr=on}}
| valvegear = Walschaerts
| valvetype =
| valvetravel =
| valvelap =
| valvelead =
| transmission =
| maxspeed = {{cvt|75|-|95|mph}}
| poweroutput =
| tractiveeffort = {{convert|49590|lbf|kN|abbr=on}}
| factorofadhesion = 4.71 – 4.74
| trainheating = Steam heat
| locobrakes = Independent air
| locobrakeforce =
| trainbrakes = Automatic air
| safety =
| operator = Canadian National Railways
| operatorclass =
| powerclass = 50%
| numinclass = 16 (U-1-a) 21 (U-1-b)
| fleetnumbers = 6000–6015 (U-1-a) 6016-6036 (U-1-b)
| officialname =
| nicknames =
| axleloadclass =
| locale =
| deliverydate =
| firstrundate =
| lastrundate =
| retiredate = 1950 (6004) 1951-1962
| withdrawndate =
| preservedunits = 6015
| restoredate =
| scrapdate =
| currentowner =
| disposition = 6015 preserved remainder scrapped
}}
{{Cite thesis|title=Canadian National Security Culture: Explaining Post 9/11 Canadian National Security Policy Outcomes|publisher=Carleton University|first=Alan|last=Stephenson|date=2016 |doi=10.22215/etd/2016-11459|doi-access=free}}{{Citation|last1=Bicknell-Johnson|first1=Marjorie|title=The Generalized Fibonacci Numbers {Cn}, Cn = Cn-1 + Cn-2 + K|date=1988|work=Applications of Fibonacci Numbers|pages=193–205|place=Dordrecht|publisher=Springer Netherlands|isbn=978-90-481-8447-7|last2=Bergum|first2=Gerald E.|doi=10.1007/978-94-015-7801-1_18}} The Canadian National U-1-a U-1-b class locomotives were three subclasses of 37 4-8-2 Mountain-type steam locomotives built for the Canadian National Railways between 1923 and 1924. They were retired between 1951 and 1962 .
| class=wikitable
|+ Table of Orders and numbers | ||||||
| Year | Subclass | Quantity || Manufacturer | Serial nos. | CN Nos. | Notes | |
|---|---|---|---|---|---|---|
| 1923 | U-1-a | 16 | Canadian Locomotive Company | 1696–1711 | 6000–6015 | 6015 preserved in Jasper, Alberta, since 1972 |
| 1924 | U-1-b | 21 | Canadian Locomotive Company | 1744–1758, 1764–1769 | |6016–6036 | All scrapped |
| 6042-6046 |
Accidents and incidents
On 1 September 1947, locomotive 6001 was involved in the Dugald rail accident. It collided with another CN 4-8-2 numbered 6046. {{abbr|No.|Number}} 6001 was later rebuilt by CN.
On 21 November 1950, locomotive 6004 was severely damaged a head-on collision with S-2-a 2-8-2 {{abbr|No.|Number}} 3538 at Canoe River, British Columbia. It was scrapped in June 1951 (as was the 3538). There was a gap of four years before the next U-1-a or U-1-b went: two were scrapped in 1955, four in 1957, six in 1958, six in 1959, eight in 1960, seven in 1961, and the last two, 6000 and 6001 in 1962.{{cite web |url=http://www.trainweb.org/j.dimech/roster/482ros.html |title=Canadian National Railways Steam Locomotive Roster, Mountain Type |accessdate=2011-06-13}}
In art
U-1-a 6004 is the subject of a 1924 publicity poster by C. Norwich. It depicts the locomotive speeding along in the foreground, while in the background is a pine-covered, snow-capped mountain peak. Across the top is the "Canadian National Railways" logotype; across the bottom are the words, "Across Canada", and in the lower left, above the artist name and date is "The Continental Limited in the Canadian Rockies"http://www.1st-art-gallery.com/C.-Norwich/Canadian-National-Railways-Poster-1924.html Canadian National Railways Poster 1924
Preservation
One locomotive has been preserved:
- CN 6015 (U-1-a) — Retired 1960; to CHRA, Delson, Quebec. On public display in Jasper, Alberta, since July 1972.