Model of a trunk engine

Petrus van der Loo, 1855

The trunk engine, invented by the British engineer John Penn, greatly improved steam propulsion for ships. Penn’s use of a ‘trunk’, or cylindrical case, housing a connecting rod, instead of a beam or side lever, made the engine more compact and allowed it to be installed horizontally across a vessel’s keel. A number of Dutch naval ships were fitted with the trunk engine. This model represents a 150 h.p. engine.

  • Artwork typescale model, demonstration model, technical model
  • Object numberNG-MC-528
  • Dimensionsheight 84.5 cm x width 82.5 cm x depth 37 cm
  • Physical characteristicswood, brass and iron

Petrus van der Loo

Model of a Trunk Engine

Netherlands, Netherlands, 1855

Provenance

...; transferred from the Ministerie van Marine (Department of the Navy), The Hague, to the museum, 1883

Object number: NG-MC-528


Entry

Model of a 150 hp trunk engine, fitted in the cross section of a ship, mounted on brass stands.

The screw shaft is shortened and fitted with a two-blade parabolic screw. The engine can be turned with a handle. The model shows two horizontal cylinders with trunks, the condenser casing with four air pumps, two steam valves with double eccentrics on the crankshaft and a control wheel on the condenser, and two steam admission valves on eccentrics.

In this direct-drive screw engine built according to John Penn’s (1805-1878) design, the piston is supplied via a round pipe called a trunk, which moves within the cylinder. The trunk replaces the piston rod and seals off the cylinder. The crank’s connecting rod is directly attached to the piston in the middle of the trunk, which allows the connecting rod sufficient space to follow the up-and-down movement of the crank while moving forwards and backwards with the trunk.

This design resulted in a much more compact transmission and allowed the engine to be placed sideways in the hull of the ship and consequently very low, beneath the waterline, better protected from possible enemy fire. Several Dutch ships were equipped with a trunk engine of this design, among them Medusa, Prinses Amalia, Admiraal van Wassenaer and Evertsen.1J.M. Obreen, Catalogus der verzameling modellen van het Departement van Marine, The Hague 1858, no. 528.

Petrus van der Loo (1806-1864) made this model under supervision of H. Huijgens, Inspector of ’s Rijks Stoomvaartdienst.


Literature

H. Huijgens, ‘De schroefmachine’, Verhandelingen en berigten betrekkelijk het zeewezen (1853), no. 2, pp. 295-332 and pl., p. 295 ff.; J.M. Obreen, Catalogus der verzameling modellen van het Departement van Marine, The Hague 1858, no. 528; J. Bourne, A Treatise on the Steam-Engine in its Various Applications to Mines, Mills, Steam Navigation, Railways, and Agriculture, London 1861 (5th ed.), pp. 40, 313-14, pl. XXX; J.M. Dirkzwager, ‘Problemen en oplossingen bij de ontwikkeling van de stoomvaart in Nederland’, Erfgoed van Industrie en Techniek 3 (1992), pp. 74-90, p. 87; J.M. Dirkzwager, ‘De Nederlandse marine als pionier in de technische ontwikkeling. Schroefvoortstuwing in het tweede en derde kwart van de negentiende eeuw’, Tijdschrift voor Zeegeschiedenis 12 (1993), no. 1, pp. 13-26, pp. 25-27; A.A. Lemmers, Techniek op schaal. Modellen en het technologiebeleid van de Marine 1725-1885, Amsterdam 1996, pp. 249-67; A.A. Lemmers and G. Boven, Nederland en Japan. Bijzondere betrekkingen 1600-1868, Den Helder 2000, p. 34; J. Holtrop et al., ‘Schroefvoortstuwing. Een 19e eeuwse technische uitdaging’, Scheepshistorie 17 (2014), pp. 48-71


Citation

J. van der Vliet, 2016, 'Petrus van der Loo, Model of a Trunk Engine, Netherlands, 1855', in J. van der Vliet and A. Lemmers (eds.), Navy Models in the Rijksmuseum, online coll. cat. Amsterdam: https://data.rijksmuseum.nl/200315817

(accessed 6 December 2025 19:33:25).

Footnotes

  • 1J.M. Obreen, Catalogus der verzameling modellen van het Departement van Marine, The Hague 1858, no. 528.