Bormann Time Fuze

Federal 5 1/4-second
Federal 5 1/4-second
Bormann time fuze

Confederate 5 1/2-second
Confederate 5 1/2-second
Bormann time fuze

The Bormann fuze is named after its inventor, Belgian Army Captain Charles G. Bormann.  The Bormann time fuze was employed by the United Stated Ordnance Department as early as 1852.  The time fuze is contained in a tin and lead disk (4).  This disk has time markings indicated in seconds and quarter-seconds graduated up to 5 1/4 seconds.  The artillerist used a metal punch to pierce the thin metal at the desired time marking.  This exposed a section in the horseshoe-shaped horizontal mealed powder train (3), which is covered by a thin sheet of tin.  When the cannon discharged, the flame from the explosion ignited this powder train.  It would burn in a uniform rate in both directions, but one end would terminate in a dead-end just beyond the 5 1/4 second mark (Confederate copies are 5 1/2 seconds).  Cross-section of the Bormann Time FuzeThe other end would continue to burn past the zero-mark, where it would travel through a channel (1) to a small powder booster or magazine (2).  This powder then exploded, sending the flame through a hole in the fuze underplug (5) to the powder chamber of the projectile.  The purpose of the brass or iron fuze underplug was to form a solid base of support for the soft metal fuze, which could have easily been damaged during firing.

Original Bormann fuze drawing from the book ORDNANCE INSTRUCTIONS FOR THE UNITED STATES NAVY: WASHINGTON, 1866.