by Paul T Carter
A checklist of Hey-Dolphin machines and their dies (with earliest and latest known dates)
To open the data files, scroll down the page and click one of the blue buttons. The data may need magnifying - you can use zoom and download options, both available when you open the file
UPDATE: Paid dies added + Introduction expanded (information updated most recently on 18 Feb. 2026)
A brief introduction to the history, development and deployment of Hey-Dolphin machines and their dies (including triangular and paid dies), complete with illustrations
Abbreviations etc (in the data files)
HD reference numbers are those created by Derek Holliday & Brian Pask for their 1978 study of Hey-Dolphin machines:
HDT = trial machine
HDM = medium speed machine
HDL = hand operated version of 'M' machine
HDE = improved version of 'M' machine (listed by the manufacturer as an 'ER' model)
HDF = 'Flier' high speed machine
Type of die:
s.c. = single circle
d.c. = double circle
Canceller element is 5 wavy lines (5W) unless stated otherwise:
7W = 7 wavy lines
7S-1R = 7 straight bars with numeral "1" embedded towards right-hand side
7W-1L-C = 7 wavy lines with numeral "1" embedded at left-hand side and "C" embedded lower left
6S = 6 straight bars
Slogans were also extensively used (not itemised here - recommendation is to refer to specialist slogan listings)
Dates annotated "HP" are from Holliday/Pask but exact die inscription and punctuation are not known
Die descriptions (e.g. 7mm gap between L and 1) - measurements are in a straight line between specified points
The British Postmark Society (BPS) exists to promote and to co-ordinate the study and collection of British postal markings (particularly of the 20th and 21st centuries), and the means and mechanisms by which they are applied, and to publish and disseminate the results of our studies.
www.britishpostmarksociety.org.uk
Listings of Krag & Universal machine postmarks can be found at the following sites:
Krag Machine Postmarks of Great Britain & Ireland
Universal Machine Postmarks of Great Britain & Northern Ireland
