HDCL produces a range of steam engines from the simple single cylinder oscillating engine to the twin cylinder horizontal engines reminiscent of Victorian pumping stations. All engines are machined from stock materials and can be supplied as self-assembly kits or fully assembled. With their clean lines they demonstrate the same mechanical principles as full size plant, as well as making elegant showpieces.

To complement the range of steam engines, HDCL also produces copper and brass boilers that fully comply with the Pressure Equipment Directive 97/23/EC and the Pressure Equipment Regulations 1999 (SI 1999/2001). All HDCL boilers:

• Use certified materials
• Are designed in accordance with AMBSC Code Part 1 Issue 7-2001: Copper Boilers
• Have a safety valve
• Have a water feed facility
• Are fitted with a sight glass (water level gauge)
• Are silver soldered throughout
• Are pressure tested
• Are supplied with a full set of documentation, certification and operating instructions

HDCL also manufactures miniature railway passenger hauling steam locomotives in 7.25 gauge. Locomotives currently in production are a 0-6-0 Holmside saddle tank, a 4-6-0 Highlander tender and a 4-6-0 St. Christopher tender. Completion of the locos is nominally scheduled for July 2006, October 2008 and April 2010 respectively.