Table:
name | railway | series | maker | dates | drive | wheel arrangement | weight | power | notes
Re 465 | BLS, Switzerland | Re 465 001-465 0018 | SLM, ABB | 1994-97 | electric | Bo-Bo | 84 t | 9,520 horsepower (7,099 kW) / [Tractive force: 300 kN (30.6 tons) | most powerful locomotive with only four axles, similar locomotives with slightly different technical data are in operation with SBB (Re 460; 119 pc/ NSB (El 18; 22 pc)/ VR (Sr2; 46 pc)/ KCRC (Hong Kong; 2 pc)
Re 6/6 | SBB, Switzerland | 11601-11689 | SLM, MFO/BBC/Sécheron | 1972 | 1975–80 | electric | Bo-Bo-Bo | 120 t | 10,908 horsepower (8,134 kW) Tractive force: 398 kN (41 tons) | in operation (October 2012), revised classification Re 620, most powerful single-frame locomotive till China Railways HXD1B appeared
Re 4/4 | BLS, Switzerland | Re 425 161-Re 425 195) | SLM / BBC | 1964-83 | electric | (Bo)(Bo) | 80 t | 6,772 horsepower (5,050 kW) Tractive force 314 kN (32 tons) | in operation (October 2012)
Ae 8/8 | BLS, Switzerland | 271-275 | SLM / BBC | 1959-66 | electric | (Bo)(Bo)+(Bo)(Bo) | 160 t | 8,806 horsepower (6,567 kW), tractive force 471 kN (48 tons) | 1 preserved in working order
AD43C | Iranian Railways(RAI) | 2001-2100 | ALSTOM | 2001 | Diesel Electric | Co'Co' | 120 t | 4,300 horsepower (3,207 kW) | about 50 locomotives are stopped because of failures in the RK215 diesel engine
Ae 6/6 | SBB, Switzerland | 11401-11520 | SLM, MFO/ BBC | 1952; 1955–66 | electric | Co-Co | 120 t | 6,000 horsepower (4,474 kW) [Tractive force: 392 kN (40 tons) | still in operation (October 2012)
Ae 6/8 | BLS, Switzerland | 201-208 | SLM / Sécheron | 1939 | electric | (1'Co)(Co1') | 140 t | 6,000 horsepower (4,474 kW), tractive force 353 kN (36 tons) | 2 remain in working order as heritage locos
Ae 8/14 | SBB, Switzerland | 11852 | SLM, MFO/ BBC | 1939 | electric | (1'A)A1'A(A1')+(1'A)A1'A(A1') | 236 t | 11,000 horsepower (8,203 kW), Tractive force: 490 kN (50 tons) | Exhibit at Swiss Transport Museum
PRR GG1 | Pennsylvania Rail Road (PRR), Penn Central, Conrail, Amtrak & NJ Transit | 4800-4938, 900-929 | Altoona Works, General Electric | 1934–43 | Electric | 2-C+C-2 (4-6-6-4) | 208.9 to 216.4 | 4,629 horsepower (3,452 kW), Tractive Effort: 65,500 lbf | Most scrapped; the prototype and 15 production locomotives preserved in museums
Class 461 | Železnice Srbije, Serbia | ŽS461-0/1, ŽS461-2 | Electroputere Craiova, Romania | 1965–91 | Electric | Co'Co' | 120 t | 7,638 horsepower (5,696 kW) | Operational in Romania, Serbia, Montenegro, Bulgaria, Hungary & Macedonia.
Allegheny | Chesapeake and Ohio Railway (C&O) & Virginian Railway (VGN) | 1600-1659 (C&O), 900-907 (VGN) | Lima Locomotive Works | 1941–48 | Steam | 2-6-6-6 | 544 t | 7,500 horsepower (5,593 kW) | Two on static display
M1 | Chesapeake and Ohio Railway (C&O) | 500-502 | Baldwin Locomotive Works | 1947–50 | Steam Turbine Electric | 2-C1-2-C1-B / (4-8-0-4-8-4) | 428 t | 6,000 horsepower (4,474 kW) | Nicknamed "Sacred Cows". Sold back to Baldwin in 1950 and scrapped.
Big Boy | Union Pacific | X4000-X4024 | ALCO | 1941-–44 | Steam | 4-8-8-4 | 548 t | 6,290 horsepower (4,690 kW) | Several on static display. / No. 4014 is to be moved from Pomona, Calif., to Cheyenne, Wyo. for restoration.
XA Triplex | Virginian Railway | 700 | Baldwin | 1916 | Steam | 2-8-8-8-4 | 383 t | N/A, Tractive Effort: 199,560 lb simple; 166,600 lb compound | Rebuilt into separate locomotives
Challenger | Union Pacific | 3985 | ALCO | 1936–43 | Steam | 4-6-6-4 | 485 t | 6,200 horsepower (4,623 kW) | Operates in excursion service; largest operational steam locomotive in 2007
GTEL 8500 'Big Blow' | Union Pacific | 1-30 (control cab), 1B-30B (turbine unit) | General Electric | 1958–61 | Gas turbine-electric | C-C+C-C | 425 t | 8,469 horsepower (6,315 kW) Over 10,000 hp at lower altitude and ambient temperatures. | Two preserved in museums. Most powerful internal combustion locomotive built.
EMD DDA40X | Union Pacific | 6900-6947 | Electro-Motive Division of General Motors | 1969–71 | Diesel-electric | D-D | 244 t | 6,600 horsepower (4,922 kW) | One operational, several in museums; largest operational single-unit diesel locomotive and the most powerful
SJ Dm3 | Malmbanan |  | ASEA | 1953–71 | Electric | 1'D+D+D1' | 273 t | 9,655 horsepower (7,200 kW) | Highest continuous tractive effort when built, most powerful locomotive using jackshafts
DB Class 103 |  |  |  | 1970–73 | Electric | Co'Co' | 114 t | 9,977 horsepower (7,440 kW) | 
060-EA | Romanian Railways(CFR) | 001-1000 | Electroputere Craiova | 1970-91 | Electric | Co'Co' | 120 t | 6,839 horsepower (5,100 kW) | Most powerful locomotive in 1970s; highest continuous tractive effort
060-EA Softronic Phoenix version | Romanian Railways (CFR) and Hungarian State Railways ( MÁV ) | 001 | 2001-2004 | Softronic Craiova | 2009–present | Electric | Co'Co' | 120 t | 8,851 horsepower (6,600 kW) | Most powerful locomotive with highest continuous tractive effort
Softronic TransMONTANA (060-EA version) | Romanian Railways (CFR) | 1 | Softronic Craiova | 2010 | Electric | Co'Co' | 120 t | 10,997 horsepower (8,200 kW) | 
SBB-CFF-FFS Re 620 | Gotthardbahn |  | BBC | 1972–80 | Electric | Bo'Bo'Bo' | 120 t | 10,527 horsepower (7,850 kW) | Most powerful single-frame locomotive when built
JR Freight Class EF200 | JR Freight |  | Hitachi Ltd. | 1990– | Electric | Bo'Bo'Bo' | 100.8 t | 8,046 horsepower (6,000 kW) | Most powerful single-frame narrow-gauge locomotive in series production
EMD SD90MAC | Union Pacific | 8500-8561 | Electro-Motive Diesel | 1996–2002 | Diesel-Electric | C-C | 210 t | 6,300 horsepower (4,698 kW) | Retired from service, some on lease with EMLX
GE AC6000CW | Union Pacific; CSX Transportation; BHP Billiton | 600-699, 5000-5016, 6070-6077, 7500-7579 (being overhauled and renumbered 69xx) | General Electric | 1996–2001 | Diesel-Electric | Co'Co' | 210 t | 6,250 horsepower (4,661 kW) | Actual HP output on early production units is 4350 hp due to use of the 7FDL engine.
Indian locomotive class WAG-9 | Indian Railways |  | Chittaranjan Locomotive Works, India | 1998 | Electric | Co'Co' | 123 t | 6,350 horsepower (4,735 kW) | Most powerful electric locomotive in India in 2010.
China Railways HXN3 | China Railways | HXN30001-HXN30300 | Dalian Locomotive, EMD | 2008– | Diesel-Electric | Co'Co' | 150 t | 6,300 horsepower (4,698 kW) | Most powerful diesel-electric locomotive in active production.
China Railways HXN5 | China Railways | HXN50001-HXN50300 | GE, CSR Qishuyan Locomotive | 2008– | Diesel-Electric | Co'Co' | 150 t | 6,250 horsepower (4,661 kW) | Most powerful diesel-electric locomotive in active production.
China Railways HXD1 | China Railways | HXD10001-HXD10220 | CSR Zhuzhou Electric Locomotive, Siemens | 2006–08 | Electric | Bo'Bo'+Bo'Bo' | 200 t | 12,874 horsepower (9,600 kW) | 
China Railways HXD2 | China Railways | HXD20001-HXD20180 | Datong Electric Locomotive, Alstom | 2006–08 | Electric | Bo'Bo'+Bo'Bo' | 200 t | 13,410 horsepower (10,000 kW) | 
China Railways HXD3 | China Railways | HXD30001-HXD30890, HXD38001-38150 | Toshiba, Dalian Locomotive | 2006–09 | Electric | Co'Co' | 150 t | 9,655 horsepower (7,200 kW) | 
China Railways HXD1B | China Railways | HXD1B0001-HXD1B0500 | CSR Zhuzhou Electric Locomotive, Siemens | 2009– | Electric | Co'Co' | 150 t | 12,874 horsepower (9,600 kW) | Most powerful single-frame locomotive in series production
China Railways HXD2B | China Railways | HXD2B0001-HXD2B0500 | Datong Electric Locomotive, Alstom | 2009– | Electric | Co'Co' | 150 t | 12,874 horsepower (9,600 kW) | Most powerful single-frame locomotive in series production
China Railways HXD3B | China Railways | HXD3B0001-HXD3B0500 | Dalian, Bombardier | 2009– | Electric | Co'Co' | 150 t | 12,874 horsepower (9,600 kW) | Most powerful single-frame locomotive in series production
China Railways HXD1C | China Railways | HXD1C0001-HXD1C0990 | CSR Zhuzhou Electric Locomotive, Siemens | 2009– | Electric | Co'Co' | 150 t | 9,655 horsepower (7,200 kW) | 
China Railways HXD2C | China Railways | HXD2C0001- | Datong Electric Locomotive, Alstom | 2010– | Electric | Co'Co' | 150 t | 9,655 horsepower (7,200 kW) | 
China Railways HXD3C | China Railways | HXD3C0001- | Dalian, Bombardier | 2010– | Electric | Co'Co' | 150 t | 9,655 horsepower (7,200 kW) | 
IORE | Malmbanan | IORE 101-IORE 126 | Bombardier | 2000–04 | Electric | Co'Co'+Co'Co' | 360 t | 14,483 horsepower (10,800 kW) / for a pair, possible to operate halves which is not usually done | Highest continuous tractive effort
Jawn Henry | Norfolk and Western Railway (N&W) | 2300 | Baldwin Locomotive Works | 1954-58 | Steam Turbine Electric | C+C-C+C | 404 t | 4,500 horsepower (3,356 kW) | Struck from the N&W roster on January 4, 1958
VL85 | Russian Railways | 270 | Novocherkassk Electric Locomotive Plant | 1983-94 | Electric | Bo'Bo'Bo'+Bo'Bo'Bo' | 300 t | 13,437 horsepower (10,020 kW) | 
WDG5 | Indian Railways |  | EMD / DLW | 2012–present | Diesel-Electric Transmission | Bo-Bo-Bo |  | 5500HP locomotive with 560KN tractive effort | The most powerful diesel locomotive in India. A vision statement of IR suggests that up to 5,000 units of this class will be manufactured by 2020.
Union Pacific Coal GTEL | Union Pacific | 80 (later 8080) | Union Pacific Omaha Shops | 1961 | Diesel-Electric + Gas Turbine-Electric | A1A-A1A+2-D-D-2 | 728 t | 7,000 horsepower (5,220 kW) (2000hp Diesel + 5000hp turbine) | Home-built experimental coal-fired gas turbine. Assembled from ALCO PA-1 UP #607, GN W1 #5018, and the tender from Challenger #3990. 215 feet (66 m) overall length; 1,457,280 pounds (661,011 kg) total weight. Unsuccessful; set aside in 1964 and scrapped in 1968.
H220 | Victorian Railways | H Class | Victorian Railways / [Newport Workshop] | 1941–1958 | 220 PSI Steam Boiler, 3 Cylinder | 4-8-4 | 265t | 3,600 HP / 2,680KW coal fired steam locomotive (50 mph) with 245KN tractive effort. | The most powerful steam locomotive, at the time built in, Australia. 1 Built. Preserved at Newport, Victoria

Question: which locomotive weighs the least?
Answer: Re 4/4

Question: does the ae 8/8 weigh more or less than the re 6/6?
Answer: more

Question: what is the difference in weight between the 060-ea and the challenger?
Answer: 365 t

Question: which locomotive had the least amount of power?
Answer: H220

Question: what is the combined weight of the big boy and the m1?
Answer: 976 t

Question: how many locomotives make the list of the largest locomotives?
Answer: 44

Question: what is the difference in weight between the re 465 and the ae 6/6?
Answer: 36 t