THE COLLIERY GUARDIAN

AND JOURNAL OF THE COAL AND IRON TRADES.

Vol. CVII;

FRIDAY, JANUARY 23, 1911.

No. 2769.

The Upkeep of Private Owners’ Wagons.

“HOT BOXES.”

[Specially Contributed.]

With the speeding up of tbe goods and mineral
traffic on the railways in this country, and the running
of long-distance through trains at high speeds, the
number of private owners’ wagons stopped for hot boxes
has increased to a serious extent. On investigation,
it is found that a large number of these stoppages
could be prevented by systematic examination and
proper workmanship. From both the private owner’s
and the railway company’s point of view the question
is a serious one. The owner is put to the expense
of repairing defects which might be avoided, and if
the wagon is for shipment or a special customer,
the delay consequent upon the stoppage for hot box
causes serious inconvenience. Apart from the cost of
repairing the hot box, and the inconvenience, there is
also the probable cost of having to renew axles long
before they should require renewing under ordinary
conditions of wear and tear, as a journal very often gets
badly cut when the box runs hot, thus necessitating it
being turned up, and it is, therefore, undersize long
before it should be. A reduction of in. in the diameter
of the journal represents about 12 per cent, reduction of
the life of the axle.

From the railway company’s point of view the increase
in hot boxes is serious, owing to the disorganisation

Fig. 1—Oil Axlebox for Use on End-tipping Wagons.

caused in stopping through trains and shunting out the
wagons. Further, a hot box may result in a journal end
being broken off if the brass happens to seize the journal
badly, and the consequences may be serious to the safe
working of the railway. It is evident, therefore, that
this question is one where the interests of the railway
and the private owner are coincident.

The causes of hot boxes may be summarised under
two heads:—

1.	Unsuitable lubricants.

2.	Defects in the wagons due either to want of
attention, defective workmanship, designs or materials.

Grease v. Oil as a Lubricant.

With regard to the first-mentioned cause, grease is the
lubricant used on at least 95 per cent, of private owners’
wagons, and it is instructive to compare this with the
large percentage of railway companies’ wagons which
are fitted with oil axle-boxes, the percentage being,
roughly, 30 per cent, oil and 70 per cent, grease.

The expert opinion of the railway companies is that
grease is not as suitable as oil under the present condi-
tions of traffic, and the companies are, therefore, fitting
oil axle-boxes on all new stock, and replacing the grease
boxes on existing stock as occasion arises.

Unfortunately, private owners are strongly prejudiced
against oil axle-boxes being fitted to their wagons, owing
to the trouble they have experienced with the wagons
which are so fitted. So strong is the prejudice that

many of them go to the additional expense of fitting
12-ton wagons with end doors, when these are not
required, so that they may fit grease boxes instead of
oil. (The private owners’ specification states “12-ton
wagons used for end-tipping may be fitted with grease
boxes, but without end doors they must be fitted with
oil axleboxes.”) Other owners are under the impression
that oil axleboxes cannot be used on end-tipping wagons
because the oil would run out of the box. There
certainly was this difficulty some years ago, but it does
not apply at the present time. Fig. 1 shows an oil
axlebox, which is designed so that when fitted to end-
tipping wagons there is no leakage of oil during tipping
operations at the docks, (See Railway Clearing House
Drawing 160.) It is the 12-ton wagons fitted with
grease axleboxes which give the most trouble, and
although 8- or 10-ton wagons may run satisfactorily, yet
the experience of the railway companies is that it is
impossible, with the present comparatively high speed of
trains, to get them to run as satisfactorily as when fitted
with oil axleboxes.

The private owner appears to have been at a disad-
vantage with regard to oil axleboxes owing to his
workmen lacking experience in the fitting up and
examination of such boxes, and most of them appear to
think that workmanship which is satisfactory for grease
axleboxes is equally satisfactory for oil axleboxes.
This, of course, is not so, as oil axleboxes require a
higher standard of workmanship in the fitting and
bedding of brasses, &c. Further, a large number of
the smaller private owners appear to lack any proper
system for the periodic oiling and cleaning of the
pads.

On comparing the number of railway companies’
wagons stopped for hot boxes with the number for
private owners’ wagons so stopped, there was a proportion
of one railway company’s to three private owners’, and
although the standard of workmanship is higher on most
railway companies’ wagons than on private owners’, yet
this does not explain the large difference in the number
so stopped. The explanation is the larger proportion of
railway wagons fitted with oil axleboxes.

As an illustration of the satisfactory running of oil
axleboxes it may be mentioned that for the whole year
1911 one of our largest railway companies ran all their
passenger coaches without one single hot box.

The best policy for the private owner is undoubtedly
to have any new stock which he has built fitted with oil
axleboxes.

Unsuitable Lubricants.

With regard to the existing stock, there is no doubt
that a large number of the stoppages can be traced to
the use of unsuitable greases and oils. During the last
few years there has been a lot of grease on the market
which contains 60 or 70 per cent, of mineral oil,, and
with a melting point of 150 to 200 degs. Fahr. Seeing
that the principle of grease lubrication is that when
the journal gets slightly* warm the grease shall melt
and run through the brass on to the journal, it will be
seen that the high melting point is a mistake, as by the
time the journal gets to a temperature of 200 degs. Fahr,
the surfaces of both the brass and the journal are
spoiled. It is essential that the melting point of wagon
grease should be between 100 and 110 degs. Fahr., and
the percentage of mineral oil should not exceed 10 per
cent. It is necessary to have a small percentage of
mineral oil, so that the grease does not get too hard in
winter or too soft in summer. Further, when a grease
melts it should do so as a whole, and not simply release
some of the oil and leave the matrix behind to clog the
feed-holes. Grease which contains china clay is liable
to clog the feed holes.

The following is considered a good specification for
wagon grease, and is, in fact, that used by one of the
principal largest railway companies:—

Fig. 2.—Form of Ticket Clip, showing Method of Fixing.

Per cent.

Palm Soap ....... 23	Y

Tallow......... 23 !	Melting point,

Mineral oil....	8	C	100 to	110 degs. Fahr.

Water.......... 46 J

It is not sufficient simply to order grease to a good
specification in order to obviate the possibility of hot
boxes. A sample should be taken from time to time and
analysed. In this way the buyer may see that he is
getting what he ordered, and the slight expense of
analysis would be more than compensated for by the
saving in I ot boxes, which would result from a proper
grease being used. The oil used should be free from
gumming properties, grit and foreign matter, and
should syphon freely. Oils which contain an excessive
quantity of free fatty acids should not be used, as they
attack the zinc and lead in the white metal. One rail-
way company uses a mixture of 33 per cent, mineral oil
with 67 per cent, olive oil with satisfactory results.
Although this is expensive, yet when one considers the
possible expense of a hot box which may result in five
years being deducted from the life of the axle, it will
be seen that the cheapest oil is the most expensive in
the long run. When the oil gets dirty it can, of course,
be cleaned and used over and over again.

Periodical Examination.

With regard to the causes under head No. 2, it is
essential that every axlebox, whether of the oil or grease
type, should be examined at fixed intervals.