The 500 series was a class of steam locomotive built in 1925 for the Portuguese State Railroad Company (CP) by the german works, Henschel & Sohn. They were 8 massive, four cylinder compound engines, with 1,90 m driving wheels and power capable of hauling 400t trains.



Built one year later than the very slightly smaller 550 series (they were originally numbered 600 until 1931 when they were also fitted with smoke deflectors), they were quickly put into service on the fast express train between Porto and Lisbon, though they had to stop at Vila Nova de Gaia, since their axle weight would not allow them to cross the bridge to Porto.

In 1930 that express took 5h19min. But in 1939, fitted with the brand new Budd passenger cars, a train hauled by 501 and 3 cars took just 3h9min, achieving speeds of 140 to 145km/h and with an average working speed of 107,8 km/h. With only 4 stops and 1 take for water, their only delay was the steep climb of Albergaria, where double heading was required.



On April, 7^th 1939, during a speed test, engine 501 hit 132km/h while hauling a 107t train. Soon after, locomotive 503 was fitted with a streamlined casing, the only time in Portugal, forming a new express train called the “Silver Arrow”. However the inefficient design of the streamlining only made her heavier, and by such slower and more fuel consuming.



Still they enjoyed a long successful mainline life until 1948, when they were replaced by the 1500 diesel class.

They spent their next years being moved from depot to depot as more and more trains where replaced with diesel traction. By 1955 they service in the south of the country was pretty much done, so their end was signed. By 1965 there were only 3 engines left, 501, 502 and 508. 502 was eventually scrapped as she was only kept as “cold reserve”. In 1969 508 was scrapped at Barreiro and 501 survived by being transferred to the still steam driven north, to Contumil depot, at Porto. She hauled several semi-fast trains on the Minho and Douro lines. However with the introduction of the 1400 class to end the steam in the North once and for all, her service was ended in 1972.



She was then subject to intensive repairs, being seen as one of the big icons of traction in the North. There were talks about putting her to preservation. Sadly on a fatal day, an electric multiple unit struck her while shunting. The damage was light, the boiler and cylinders remained intact but still she was sent back to Entroncamento to wait assessment. After much public turmoil, she was quickly scrapped. And with that it went the last of the fastest most iconic locomotive on the Portuguese railroads.

Engines: 501 to 508 (8)
Builder: Henschel & Sohn (Kassel, Germany) in 1925

Operator: CP
Class: 500

Type: Tender and 4-cylinder compound
Config: 4-6-2 (Pacific)
Gauge: 1668 mm (Iberian)

Lenght: 20 890 mm
Height: 4 400 mm

Drive wheel diameter: 1 900 mm
Piston stroke: 640 mm
Valve gear: Walschaert
Cylinders: 2 HP 380 mm + 2 LP 580 mm

Boiler pressure: 16 kg/cm^2
Traction effort: 8 974 kg
Weight: 138, 840 t (87,640 t loco)
Fuel: 6,0 t coal / 11 160 L oil
Water: 23 000 L

Heating surface: 183,17 m^2
Super heater surface: 69,0 m^2
Grill: 2,56 m^2
Tubes 30[x] 125x133mm + 117[x] 50x55mm

Brakes: Manual, Vacuum.
Lub: pump.
Water: 2 injectors + Friedmann.