Ferrovie dello Stato 2-8-0 Locomotives in Italy


Class Details by Steve Llanso of Sweat House Media

Class Gruppo 720 (Locobase 11408)

Data from "Locomotives for the Italian Government Railways," Railroad Gazette, Vol XLII [42], No 2 (11 January 1907), pp. 50-51; and DeGolyer, Volume 29, p. 124. Additional data from diagram published on DUEGI EDITRICE's TuttoTreno website [], a modelling site with a great deal of data. (visited 11 July 2004); and "Postcards showing two Baldwin-designed and built steam locomotive classes", Posted byu/Historynerd88

September 2021 on Reddit's r/TrainPorn at [], last accessed 13 March 2022. Works numbers were 28570-28571, 28630-28633 in July 1906; 28707, 28715-28717 in August.

Delivered at the same time as the Gruppo 666 locomotives (Locobase 11407), this set of Consoliations were less novel in their approach. The two-cylinder simple-expansion power train differed from many of the European builders' products supplied to the FS in the same period. Like the 666 engines, these were the biggest and most powerful 2-8-0s on Italian rails at the time, although they would soon be ovetaken by other classes.

u/Historynerd88 commented that while they were less complicated, they did experience "some teething troubles, some structural weaknesses that forced to lower [sic] the tractive effort below the boiler's potential". Even the pony truck cost problems. So they were relegated to secondary service until the 1930s when they were withdrawn.

But, u/Historynerd88 continues, that did not mean the experiment was "nothing but a failure." The class's bogie tender design, after some alterations, became "by and large the standard tender of the Italian steam locomotives. The 2'2'T22 tenders were known as the "'American-type tender'".


Class Gruppo 730 - series 1 (Locobase 10630)

Data from "Compound Goods Locomotive, Italian State Railways," The Locomotive Magazine, Vol XIII (15 November 1907), p. 203.

According to [] (an Italian-language site that features all FS designs), there were two batches: 7301-7360, 7361-73100-73199. The first of the class was delivered in 1906 with 490-mm (19.29") HP cylinders, the only significant difference from the second series, which is shown in Locobase 6625.


Class Gruppo 730 - series 2 (Locobase 6625)

Data from the US Military Railway Service's Equipment Data Book for Italian Locomotives supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

According to [] (an Italian-language site that features all FS designs), there were two batches: 7301-7360 and 7361-73199. The first of the class was delivered in 1906 with 490-mm (19.29") HP cylinders; see Locobase 10630 . Henschel & Sohn produced 80 of this slightly more powerful variant with Italian builders Ansaldo (25), Breda di Milano (15), and OM Saronno (10) adding to the class.

Even though nearly 200 were produced, the FS soon adopted a simple-expansion, superheated design -- the Gruppo 740 -- that far outshined these compounds. See Locobase 3368.


Class Gruppo 735A (Locobase 3676)

Data from Ugo Poddine as contributor to Bryan Attewell ([] Steam locomotive simulator (April 2000). Additional data from the US Military Railway Service's Equipment Data Book for Italian Locomotives supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Schenectady works numbers were 56789-56848, 57382-57421 in 1917. (The last seven locomotives were lost at sea.) Montreal supplied 60868-60882 in 1918. (The first seven replaced the Schenectady engines that were lost at sea.)

Modeled after the Grupo 740s (Locobase 3678) that had been in production since 1911, this first group approximated the Italian design in boiler and grate size. The superheater tube diameter was just a bit larger, but otherwise the reproduction was close in most dimensions. The 740's Zara truck was replaced by a Bissel truck; concerns that the "Wilsons", as they were nicknamed, would not be as steady on the track proved unfounded.

In fact, Alco delivered the goods in all respects. The engines were tough and reliable and even the 735As met the 980 hp at 27 mph (43.5 km/h) requirement. The greater number of 735Bs featured changes to the boiler, firebox, and grate; see Locobase 3677.

Their only shortcoming was a greater appetite for water and coal.

Both versions of the North American-built 735s served into the 1960s.


Class Gruppo 735B (Locobase 3677)

Data from Ugo Poddine as contributor to Bryan Attewell ([] Steam locomotive simulator (April 2000). Additional data from the US Military Railway Service's Equipment Data Book for Italian Locomotives supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Pulverized Coal Burning Equipment for Europe", Railway Mechanical Engineer, Volume 94,No 9 (September 1920), pp. 581-582. Schenectady works numbers were 60583-60732 in 1919. Montreal's works numbers were 60733-60882

This was the larger proportion of a standard Consolidation design imported from the US during and after World War I. This group had a slightly larger boiler and grate than the earlier set described in Locobase 3676, the difference coming from tubes that measured one foot (305 mm) longer. According to the MRS's horsepower rating, the extension increased output by 100 hp, to 1,080 at 27 mph. Normal boiler output was 19,580 lb (8,881 kg) per hour.

RME's September 1920 described equipment developed and manufactured by Fuller Engineering Company of Allentown, Pa to burn pulverized lignite coal in conventional fireboxes. Two of the FS Consolidations were delivered with the equipment, which used four steel feed screws in the tender's bottom were driven by a two-cylinder steam engine to move the pulverized fuel to the 29" diameter feed hose onto the grate. The firebox was fitted with a brick arch

Poddine notes that these 735s, together with the 740 class (Locobase 3678), made up the "most typical engines of Italian railways." Both versions of the North American-built 735s served into the 1960s.


Class Gruppo 740 (Locobase 3678)

Data from Ugo Poddine as contributor to Bryan Attewell ([] Steam locomotive simulator (April 2000); confirmed and expanded by [] (June 2004). Additional data from the US Military Railway Service's Equipment Data Book for Italian Locomotives supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Some Italian Locomotives at the Turin Exhibition", Locomotive, Volume XVII [29] (15 November 1911), p. 246; and "The Caprotti Locomotive Valve Gear", Locomotive Magazine, Volume XXIX [29] (15 October 1923), pp. 299-302.

The 740 class entered service before the 735s and were home-built. "It was the most characteristic steam class of Italian railways ..." says Poddine. Working from the basis of the Gruppo 730 saturated-steam, two-cylinder compounds, Ansaldo delivered a batch in 1911 that immediately showed a 10% increase in horsepower over the 730. Its widespread use stemmed from its "enormous versatility", says one source, which in turn is attributable to the relatively axle loading. They also were capable of 65 km/h (40 mph), which suited these freight haulers to some mixed-traffic service as well. Simple, reliable, economical to maintain and to operate -- the 740s manifested all of the qualities that put steam traction in its best light.

NB: The Locomotive report expressed gratitude to Ansaldo Armstrong's Dr Guido Boralevi for the data he supplied on the Gruppo 740. They differ to a small degree in most respects from the other sources.

Henschel supplied most of the post war 740s as reparations for damages inflicted on Italy in World War I. The tenders on these locomotives had three axles instead of two bogie trucks.

The ISR installed Arturo Caprotti's valve gear on 740-324 for trials. According to early reports, LM's 1923 account declared, resulted in "an economy of 15-16% in water consumption." The "mechanical aspect" was "also most satisfactory" with the components looking "as new" after 20,000 km (12,422 miles) and the valves maintaining "perfect tightness."


Class Gruppo 744 (Locobase 3681)

Data from Ugo Poddine as contributor to Bryan Attewell ([] Steam locomotive simulator (April 2000). Additional data from the US Military Railway Service's Equipment Data Book for Italian Locomotives supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Mixed traffic locomotives that were, according to Poddine, the last steam locomotives to be built from scratch in Italy. The first 25 had Walschaert gear, the last 25 used Caprotti valve gear. Max speed was approx 45 mph (72.5 kph). The class was credited by the MRS with 22,440 lb of steam per hour and rated at 1,250 hp at 45 mph, exactly the same numbers as the Gr 685 2-6-2.


Class Gruppo 745 (Locobase 3682)

Data from Ugo Poddine as contributor to Bryan Attewell ([] Steam locomotive simulator (April 2000). Additional data from diagram published on DUEGI EDITRICE's TuttoTreno website [], a modelling site with a great deal of data. (visited 11 July 2004). See also "2-8-0 Locomotive, Series 745, Italian State Railways", Locomotive Magazine, Volume XXI [21] (15 May 1915), p. 105-108. US Military Railway Service's Equipment Data Book for Italian Locomotives supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Ansaldo and Breda combined to deliver the class.

Mixed traffic locomotives built with inside cylinders.

LM's report spells out the "somewhat difficult problem presented by the conditions encountered in the exploitation of certain Italian Mediterranean and Adriatic coast lines." Small-radius curves and tough gradients of 1.3 to 1.6% are "common" and in some cases as "severe" as 1.8% set the table. And the demands of perishable-goods trains with trailing loads of 400-500 tons to be hauled at 75 kph (47 mph) called for power and big boilers.

In the rest of Europe, said LM, such demands would be met by 4-6-2 (Pacifics), but axle load restrictions to 14.5 tons led the Italian State to adopt a superheated Consolidation design. The unusual combination of outside valves and inside cylinders combined in single weight-saving castings was dictated by weight and high piston speeds, thought LM, explaining that it was"likely that inside cylinders offer some advantage over outside in improving the steadiness of the engine as a vehicle."

Of course, inside cylinders meant a cranked driving axle "of the utmost possible strength and bearings of ample dimensions" with a center portion laid out in a diagonal forging. The Fremont crank discs had "peculiarly shaped openings" to redirect stress through a line of least resistance to avoid cracks between the axle and the crank pins. Placing the valve motion provided for better access between the frames and the adoption of larger bearings.

The designers also made use of the Italian Zara truck, a design similar to the Krauss-Helmholz truck found elsewhere in combining the front carrying truck with the first adhesive axle's drivers, which were allowed some lateral movement.

Innovative, powerful, and, most likely, very expensive to build, the class was limited to twelve engines.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassGruppo 720Gruppo 730 - series 1Gruppo 730 - series 2Gruppo 735AGruppo 735B
Locobase ID11408 10630 6625 3676 3677
RailroadFerrovie dello Stato (FS)Ferrovie dello Stato (FS)Ferrovie dello Stato (FS)Ferrovie dello Stato (FS)Ferrovie dello Stato (FS)
CountryItalyItalyItalyItalyItaly
Whyte2-8-02-8-02-8-02-8-02-8-0
Number in Class1060130108285
Road Numbers7201-72107301-73607361-7399, 73100-73190735.001-735.108735.244 a 735.393, 109 a 243.
GaugeStdStdStdStdStd
Number Built1060130108285
BuilderBurnham, Williams & CoHenschel & SohnseveralAlco-SchenectadyAlco
Year19071906190719171917
Valve GearStephensonWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.25 / 4.6515.42 / 4.7015.42 / 4.7014.76 / 4.5014.76 / 4.50
Engine Wheelbase (ft / m)23.66 / 7.2123.95 / 7.3023.95 / 7.3023.29 / 7.1023.29 / 7.10
Ratio of driving wheelbase to overall engine wheelbase 0.64 0.64 0.64 0.63 0.63
Overall Wheelbase (engine & tender) (ft / m)53.41 / 16.2850.07 / 15.2650.07 / 15.2654.72 / 16.6855.31 / 16.86
Axle Loading (Maximum Weight per Axle) (lbs / kg)32,408 / 14,70030,865 / 14,00031,480 / 14,27932,560 / 14,76933,001 / 14,969
Weight on Drivers (lbs / kg)124,341 / 56,400123,459 / 56,000123,201 / 55,883122,980 / 55,783129,799 / 58,876
Engine Weight (lbs / kg)138,891 / 63,000143,300 / 65,000144,321 / 65,463140,141 / 63,567147,180 / 66,760
Tender Loaded Weight (lbs / kg)100,090 / 45,40070,107 / 31,80070,180 / 31,833110,440 / 50,095110,440 / 50,095
Total Engine and Tender Weight (lbs / kg)238,981 / 108,400213,407 / 96,800214,501 / 97,296250,581 / 113,662257,620 / 116,855
Tender Water Capacity (gals / ML)5280 / 203300 / 12.503300 / 12.506133 / 23.236133 / 23.23
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 6.60 / 6 6.60 / 6 6.60 / 6 6.60 / 6 6.60 / 6
Minimum weight of rail (calculated) (lb/yd / kg/m)52 / 2651 / 25.5051 / 25.5051 / 25.5054 / 27
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)55.10 / 140054.30 / 137953.90 / 137053.90 / 137053.90 / 1369
Boiler Pressure (psi / kPa)203.10 / 14227.70 / 15.70198.70 / 13.70174 / 12174 / 12
High Pressure Cylinders (dia x stroke) (in / mm)20.08" x 25.98" / 510x66019.49" x 27.56" / 495x700 (1)21.26" x 27.56" / 540x700 (1)21.26" x 27.56" / 540x70021.26" x 27.56" / 540x700
Low Pressure Cylinders (dia x stroke) (in / mm)29.53" x 27.56" / 750x700 (1)29.53" x 27.56" / 750x700 (1)
Tractive Effort (lbs / kg)32,820 / 14886.9225,993 / 11790.2425,708 / 11660.9734,181 / 15504.2634,181 / 15504.26
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.79 4.75 4.79 3.60 3.80
Heating Ability
Tubes (number - dia) (in / mm)260 - 2.008" / 51255 - 2.047" / 52255 - 2.047" / 52156 - 1.969" / 50155 - 1.969" / 50
Flues (number - dia) (in / mm)21 - 5.394" / 13721 - 5.394" / 137
Flue/Tube length (ft / m)14.44 / 4.4016.40 / 516.40 / 515.32 / 4.6716.40 / 5
Firebox Area (sq ft / m2)122.17 / 11.35129.23 / 12.01125.89 / 11.70115.17 / 10.70115.17 / 10.70
Grate Area (sq ft / m2)37.67 / 3.5030.24 / 2.8130.45 / 2.8330.79 / 2.8634.12 / 3.17
Evaporative Heating Surface (sq ft / m2)2085 / 193.702154 / 200.192154 / 200.201644 / 152.701746 / 162.21
Superheating Surface (sq ft / m2)459 / 42.66459 / 42.64
Combined Heating Surface (sq ft / m2)2085 / 193.702154 / 200.192154 / 200.202103 / 195.362205 / 204.85
Evaporative Heating Surface/Cylinder Volume218.96452.69380.45145.18154.19
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation76516886605053575937
Same as above plus superheater percentage76516886605065367184
Same as above but substitute firebox area for grate area24,81329,42625,01424,44824,248
Power L152805283454887678908
Power MT374.47377.36325.54628.65605.21

Principal Dimensions by Steve Llanso of Sweat House Media

ClassGruppo 740Gruppo 744Gruppo 745
Locobase ID3678 3681 3682
RailroadFerrovie dello Stato (FS)Ferrovie dello Stato (FS)Ferrovie dello Stato (FS)
CountryItalyItalyItaly
Whyte2-8-02-8-02-8-0
Number in Class4705012
Road Numbers744 001-025, 101-125745.001 - 745.012
GaugeStdStdStd
Number Built4705012
Builderseveralseveral
Year190719271912
Valve GearWalschaertvariousWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)14.76 / 4.5018.40 / 5.6118.37 / 5.60
Engine Wheelbase (ft / m)23.29 / 7.1026.90 / 8.2026.90 / 8.20
Ratio of driving wheelbase to overall engine wheelbase 0.63 0.68 0.68
Overall Wheelbase (engine & tender) (ft / m)55.58 / 16.9457.91 / 17.65
Axle Loading (Maximum Weight per Axle) (lbs / kg)31,020 / 14,07031,747 / 14,400
Weight on Drivers (lbs / kg)124,340 / 56,400128,480 / 58,278126,281 / 57,280
Engine Weight (lbs / kg)146,607 / 66,500154,400 / 70,035150,699 / 68,356
Tender Loaded Weight (lbs / kg)110,451 / 50,100100,000 / 45,359101,419 / 46,003
Total Engine and Tender Weight (lbs / kg)257,058 / 116,600254,400 / 115,394252,118 / 114,359
Tender Water Capacity (gals / ML)4839 / 18.334950 / 18.754950 / 18.75
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 6.60 / 6 6.60 / 6 6.60 / 6
Minimum weight of rail (calculated) (lb/yd / kg/m)52 / 2654 / 2753 / 26.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)53.90 / 137064.20 / 163164.20 / 1630
Boiler Pressure (psi / kPa)174 / 11.70174 / 12174 / 12
High Pressure Cylinders (dia x stroke) (in / mm)21.3" x 27.6" / 540x70023.6" x 28.3" / 600x72022.83" x 28.35" / 580x720
Tractive Effort (lbs / kg)34,360 / 15585.4536,311 / 16470.4134,041 / 15440.76
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.62 3.54 3.71
Heating Ability
Tubes (number - dia) (in / mm)135 - 2" / 51154 - 2.047" / 52154 - 2.047" / 52
Flues (number - dia) (in / mm)21 - 5.23" / 13321 - 5.25" / 13321 - 5.236" / 133
Flue/Tube length (ft / m)16.38 / 4.9919.04 / 5.8019.03 / 5.80
Firebox Area (sq ft / m2)129.12 / 12129.12 / 12129.17 / 12
Grate Area (sq ft / m2)30.13 / 2.8037.70 / 3.5037.67 / 3.50
Evaporative Heating Surface (sq ft / m2)1645 / 152.882063 / 191.732064 / 191.76
Superheating Surface (sq ft / m2)444 / 41.26544 / 50.56543 / 50.47
Combined Heating Surface (sq ft / m2)2089 / 194.142607 / 242.292607 / 242.23
Evaporative Heating Surface/Cylinder Volume144.52143.98153.66
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation524365606555
Same as above plus superheater percentage634479377931
Same as above but substitute firebox area for grate area27,18527,18527,195
Power L18633988110,530
Power MT612.27678.20735.33

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