Field Trial of Optical Fibre Cable-TV System Optical Fibre System for ...

202
Fig. 11
Transmission equipment for 34 Mbits/ at Embankment
changes require only a minimum of routine
and preventive maintenance. A major
change was to provide more staff on
day duties and less on shift work. A new
grade entitled Communications Equipment
Technician has also been introduced
to cater for the increased sophistication
of the new network. The staff
should provide better flexibility as they
will be expected to deal with the more
complex faults on all types of communication
systems including train radio,
closed circuit television, public address
as well as the new telephone system.
Training
To achieve this reorganisation it has required
extensive retraining of existing
staff. Formal training was supplied by
the contractor responsible for the new
system supported by field training by attaching
staff to his installation personnel.
In practice, due to the diversion of
resources to the installation of the new
system, it was not possible to train the
staff to the degree of competence necessary
to maintain the new system with
100% confidence from day one. Assistance
was therefore obtained from the
contractor for the first six months of service
in the form of one man on permanent
day attachment to London Underground.
As previously mentioned our
technicians quickly became proficient
in dealing with defects, and the services
of the contractor personnel on a regular
basis have now been terminated.
An important aspect of the new maintenance
discipline has been the need to
closely control spare boards and equipment.
With the St rowger equipment only
a small number of items were essential
to the operation of the whole exchange
and these could easily be controlled.
Now it is vital to ensure that spare
boards and parts are available at all
times as the lack of a board could result
in extensive downtimes with little room
for alternative temporary repairs. To this
end a computerised inventory system
will soon be introduced to record and
control all spare boards.
The transition from electromechanical
to an electronic system has caused
many long established organisation
procedures and methods to be reviewed,
and many changes have now
been implemented to create an
organisation more suited to the electronic
age.
References
1. Knipe.V.T.A.: The Use of Optical Fibre
Cables in the Modernisation of the
London Transport Automatic Telephone
System. IRSE Conference 198*
2. Mörlinger, R.: MD110 - a Digital SPC
PABX. Ericsson Rev. 59 (1982):1,PP
2 — 13.
3. Reinius, J., Svensson, B. and Åkerlund.
S.-O.: Digital Signal Processing in System
MD 110. Ericsson Rev. 59(1982) :i,
4. Reinius, J. and Sandström, 0.: DIAVOX
Courier 700. Digital System Telephone
for MD 110. Ericsson Rev. 59 (1984'•
pp. 58-66.
5. Barnicoat, G., Boman, L. and Ulander
O.: Dafa Communications m MO""-
Ericsson Rev. 59 (1982):2, pp. 67-'=.
6. Hedman, J.-O.: MD110 in the Auto^
mated Office. Ericsson Rev.
(1983):2, pp. 88-93.