piece-drilling-process

A process developed at the beginning of the 18th century to produce cannons. The body of the cannon was cast as one solid piece, and the barrel was subsequently hollowed out.

Until well into the 17th century, cannons in Europe were produced by the hollow casting method. The cannon’s ‘soul’, the barrel, was produced by placing a core in the cannon mould around which the bronze casting would solidify. The barrel was then hand-reamed to a smooth finish. The whole process, however, was beset by many problems: the core might not be placed correctly in the mould, the metal might cool unevenly, the walls might be too thin.

Johann Maritz (1680–1743), a turner from Burgdorf in the service of Berne, was among the first in 1715 to introduce the piece-drilling process. The cannons were first manufactured as a solid piece, then placed on a huge lathe in order to hollow out the barrel. The drill was held in place while the barrel was firmly clamped and turned around its axis, allowing the operator to reproduce the precise drill dimensions.

Maritz and later his son, Jean Maritz the Younger, introduced the piece-drilling process while in the service of the kings of France (Fonderie Ruelle, Fontes d’artillerie à Lyon, Strasbourg cannon foundry) and later in Spain (Barcelona, Sevilla). The process was introduced in the Netherlands and in Great Britain by the Dutchman Jan Verbruggen.

These machines, basically oversized lathes, were extremely valuable and not at all easy to produce. The Ruelle piece-drilling machine introduced by Jean Maritz the Younger in the middle of the 18th century remained in operation until the 1840s. Further proof of the very great value of a good piece-drilling machine is the fact that Napoleon stole the drilling machine belonging to the cannon foundry of Hanover.

Johann Conrad Fischer had a special biographical link to the Stockholm piece-drilling machine: His father, Johann Conrad Fischer the Elder, had worked for some years under Andreas Schalch in the Royal Foundry in Woolwich, which also had a piece-drilling machine. It was this machine that was the model for the one in Stockholm.

This know-how spread towards the end of the century into the newest area of the machine-tool industry, namely the production of steam engines. As with cannons, the cylinder of the steam engine was cast as a single piece and the cylinder was then bored. To ensure the machine’s perfect operation, the drilling of the cylinder had to be as precise as possible. The pioneers of steam engine production, the firm of Boulton und Watt, employed the cannon-drilling process.

Cite as: piece-drilling-process. In: Travel Reports of a Pioneer: Digital Edition of the Travel Journals of Johann Conrad Fischer 1794–1851. Published by Franziska Eggimann. Edited by Franziska Eggimann, Nicolau Lutz, Valerija Rukavina und Christopher Zoller-Blundell. Schlatt 2023, Version 1.2, https://johannconradfischer.com/en/keywords/gfa-keywords-8398, viewed on 7 June 2025.