The Ferrovie dello Stato (FS; Italian State Railways) Class 744 (Italian: Gruppo 744) is a class of 2-8-0 steam locomotives; they were the last orthodox steam locomotives built for the FS.[1][2]

FS Class 744
FS Class 744.003 as preserved at Cagliari railway station
Type and origin Power type Steam Builder Gio. Ansaldo & C., Ernesto Breda, Officine Meccaniche Build date 1927-9 Total produced 50
Specifications Configuration: ​  • UIC 1'D h2 Gauge 1,435 mm (4 ft 8+1⁄2 in) standard gauge Leading dia. 960 mm (37.80 in) Driver dia. 1,630 mm (64.17 in) Length 11,615 mm (38 ft 1+1⁄4 in) Axle load 14.6 tonnes (14.4 long tons; 16.1 short tons) Loco weight 70.2 tonnes (69.1 long tons; 77.4 short tons) Tender weight 50 tonnes (49 long tons; 55 short tons) Fuel type Coal Fuel capacity 6,000 kg (13,000 lb) Water cap. 22,000 litres (4,800 imp gal; 5,800 US gal) Firebox:  • Firegrate area 3.5 m2 (38 sq ft) Boiler pressure 12 kg/cm2 (1,180 kPa; 171 psi) Heating surface 191.7 m2 (2,063 sq ft) Superheater: ​  • Heating area 50.5 m2 (544 sq ft) Cylinders Two, simple Cylinder size 600 mm × 720 mm (23.62 in × 28.35 in) Valve gear Walschaerts, Caprotti
Performance figures Maximum speed 80 km/h (50 mph) Power output 1,400 CV (1,030 kW; 1,380 hp) Tractive effort 14,800 kgf (145 kN; 32,600 lbf)

Design and construction

The Class 744 derived from the earlier Class 745 locomotives, with which they shared the boiler and the wheelbase; they were only partially successful, as their inside cylinders (chosen to keep the axle load as low as possible) forced the use of inadequately dimensioned big ends, which tended to run hot. The weight limits had been subsequently relaxed, and a 14.6 tons (later elevated to 14.85 for the Caprotti locomotives) axle load was permitted; this allowed the designers to place the two cylinders outside, avoiding the issue altogether.[3][4]

The first batch of 25 locomotives was outshopped by Breda in 1927, and had Walschaerts valve gear. The subsequent 25 locomotives were built by Ansaldo (15) and Officine Meccaniche (10) in 1928, and were all fitted with Caprotti valve gear; these were originally classified Class 743, but in 1930 they were reclassified Class 744.1XX.[5][6]

Operations and modifications

Designed for mixed traffic working, the Class 744 was mainly allocated to southern Italy, with eighteen of them stationed at Salerno for service on the Salerno–Reggio di Calabria railway, and a further twenty at Palermo and Catania. After the Tyrrhenian line was electrified, some locomotives were transferred to northern Italy, while others were assigned to Sardinia. In 1956 the 744.024 was experimentally fitted with a Giesl ejector. The Class 744 was completely withdrawn from service in the 1970s.[7][6]

Preservation

Two Class 744 locomotives have survived into preservation:

• The 744.003, with Walschaerts valve gear, is preserved as a static exhibit at Cagliari railway station;
• The 744.118, with Caprotti valve gear, was initially kept at the National Railway Museum of Pietrarsa, before being transferred to Pistoia, pending a possible restoration to active service for heritage trains.

References

Bibliography

• Cornolò, Giovanni (July 2014). "Locomotive a vapore". TuttoTreno (3).
• Kalla-Bishop, Peter Michael. Italian state railways steam locomotives : together with low-voltage direct current and three-phase motive power. Tourret. ISBN 0905878035.