Improvements in Stern Tubes for Screw Steamers.
Year: 1894

page_text: Date of Application, 12th Apr., 1894
Complete Specification Left, 28th Aug., 1894-Accepted, 29th Sept., 1894
JAMES WILLIAM DONOVAN 5 Ash Place Sunderland Engineer do hereby
declare the nature of this invention to be as follows:-
This improvement cousists of means whereby propeller shafts are protected from
corrosion.
The stern tube is enlarged about six feet forward of the outer end of stern post
and a stuffing box formed (for packing) with gland to same; from this point to a
short distance from aftermost water tight bulkhead the stern tube is cut away at
each side to allow access to gland for packing same, and also to expose the part of
propeller shaft not covered by the brass liners; the stern tube is secured to stern
post and aftermost water-tight bulkhead in the usual manner, and has the usual
stuffing box and gland for packing at forward side of bulkhead.
By this means the propeller shaft can then be packed and made water tight
abaft the aftermost water tight bulkhead as well as at the forward side, so that the
part of propeller shaft not covered by brass liners protected from the action of
the sea water and is also accessible at any time for examination.
J. W. DONOVAN...
Improvements in Stern Tubes for Screw Steamers.
I. JAMES WILLIAM DONOVAN, Engineer, of 5 Ash Place, Sunderland, do
hereby declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
This improvement in and connected with stern tube bearings for propeller shafts
consists of means whereby propeller shafts are protected from the corrosive action
of the sea water and to facilitate the examination of said shafts.
I will now proceed to explain by reference to accompanying drawings and the
same letters of reference agree in all the figuros.
Figure 1 is a longitudinal section of stern tube A fitted in the usual manner to
stern post B and to peak bulkhead C. D is the propeller shaft shown in its
working position. E and E' are the brass sleeves or liners contracted on to the
shaft and made water tight so as to prevent the sea water coming in contact with
the portion of shaft they cover, the brass sleeve or liner E on after end of shaft is
put on in one length and the shaft thus covered by the brass sleeve or liner E runs
as usually fitted on a lignum vitæ bearing in the after end of stern tube. The
stern tube A is enlarged at F so as to form a stuffing box G and gland H so
placed that the forward portion of brass sleeve or liner E runs in the gland H.
The stern tube A at the enlarged portion F to L has openings as shown at J and J',
Figures 2 and 3, and the portion of the stern tube when tube is being arranged in
vessel may be so placed that the openings J and J' face port and starboard side of
vessel, or at top and bottom as may be most convenient. By this means access is
given to the gland H for packing same and also for examination of shaft at
portion K not protected by the brass sleeve or liners.
The stern tube A is reduced at L just abaft the peak watertight bulkhead C
and has the usual stuffing box G and gland Hat fore side of bulkhead. The

page_text: stern tube is secured to the peak bulkhead C by the flange P and two half
plates O and O' to facilitate the passing of the large portion of stern tube through
said bulkhead, which plates O and O¹ are rivetted and caulked after tube is in
place, thus making a watertight joint on bulkhead C; or the spigot on tube and
flange Pat bulkhead may be enlarged to correspond with increased diameter of
stern tube and bolted direct to bulkhead C without the intervention of the half
plates O and O¹.
Figure 2 is a section through e, f, Figure 1 and shows the portion of stern tube
cut away at J and J.
Figure 3 is a part sectional elevation at g, h, Figure 1 and shows gland H.
Figure 4 is end elevation on bulkhead and shows flange P of stern tube also the
plate joint and O' part of bulkhead C and gland H¹.
Figure 5 is longitudinal elevation of stern tube showing full length of openings.
By fitting stern tubes in the manner described, the propeller shaft can be packed
and made watertight in the after peak by means of the gland H (as well as at the
fore side of bulkhead), and by means of the opening in stern tube at each side or
top and bottom as the tube may be placed the exposed part of propeller shaft K is
protected and runs free from the action of the sea water and is always accessible
for examination and, painting, and the life of the shaft therefore considerably
lengthened.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what
1 claim is :-
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°
1. A stern tube with openings J, J', as described and shown in Figures 1, 2, 3, 4
and 5 with glands H and H.
2. Stern tubes with two glands and longitudinal openings, as hereinbefore
described for the purposes set forth.
The 28th day of Anonst 1894
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said James William Donovan.
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said James William Donovan.