Page 188 - Know and Understand Centrifugal Pumps

Pump Shaft

Packing

History

In the beginning of recorded time, primitive man began building boats
for fishing and to explore his world. The rudder appeared in some of
the original designs of boats. The rudder was a specialized type of oar.
It was composed of a handle on the upper end, and a shaft mostly
mounted in a vertical fashion. The shaft passed through a hole in the
bottom of the boat. Often the hole was below the water line. The lower
end of the rudder shaft was submerged into the water. The lower end of
the shaft was designed with a flat palette or paddle. This flat paddle was
called the ‘tiller’. The sailor up in the boat could rotate the rudder and
thus steer or navigate the boat with the tiller in the water below.

The hole in the bottom of the boat, where the rudder shaft passed
through, was a point of leakage where water would enter into the boat.
So the early boat builders had to design a method of preventing the
entrance of water. They designed a box-type housing around the hole
with a circular gland type press. The sailors would stuff or pack their old
clothes, hair, rotten ropes, old sails and leather scraps into the box-type
housing. The word ‘stuffing box’ was born. The purpose of the circular
gland type press was to squeeze and compress the stuffing, called
‘stopa’ (pronounced STOH-pah), into the box, creating a seal between
the rudder shaft and the hole in the bottom of the boat. This prevented
the entrance of water into the boat. The term ‘stuffing box’ is still used
today referring to pump design. (In Spanish the word for stuffing box is
‘prensaestopa’ or literally ‘stopa press’.)

Vegetable fibers

Aboard every sailing ship, there was a sail maker/tailor. This tailor’s job

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