Being asked to read a paper before your institute, I have chosen this
subject, as I think no part of the marine engine has given so much
trouble and anxiety to the seagoing engineer; and from the list of
shipping casualties in the daily papers, a large proportion seem due
to the shafting, causing loss to the shipowner, and in some instances
danger to the crew. My endeavor is to put some of the causes of these
casualties before you, also some of the remedies that have tended to
reduce their number. Several papers have been read on this subject,
chiefly of a theoretical description, dealing with the calculations
relating to the twisting and bending moments, effects of the angles of
the cranks, and length of stroke--notably that read by Mr. Milton
before the Institute of Naval Architects in 1881. The only _practical_
part of this paper dealt with the possibility of the shafts getting
out of line; and regarding this contingency Dr. Kirk said that "if
superintendent engineers would only see that the bearings were kept in
line, broken crank and other shafts would not be so much heard of." Of
course this is one of those statements made in discussions of this
kind, for what purpose I fail to see, and as far as my own experience
goes is _misleading_; for having taken charge of steamers new from the
builders' hands, when it is at least expected that these shafts would
_be in line_, the crank shaft bearings heated very considerably, and
_continued_ to do so, rendering the duration of life of the crank
shaft a short one; and though they were never what is termed out of
line, the bearings could _not_ be kept cool without the use of sea
water, and occasionally the engines had to be stopped to cool and
smooth up the bearing surfaces, causing delays, worry, and anxiety,
for which the engineer in charge was in no way responsible. Happily
this state of what I might call _uncertainties_ is being gradually
remedied, thanks being largely due to those engineers who have the
skill to suggest improvements and the patience to carry them out
against much opposition.

These improvements in many instances pertain to the engine builder's
duties, and are questions which I think have been treated lightly;
notably that of insufficient bearing surface, and one of the principal
causes of hot bearings, whereby the oil intended for lubrication was
squeezed out, and the metal surfaces brought too close in contact; and
when bearings had a pressure of 200 l