Comments have been made that the signalling system on the SLR causes a
limitation on the speed capability of trams.

The signals are mainly from station to station, except at junctions which
can be traversed at line speed with a clear signal. The crossovers at John
Street Square and Wentworth Park are approached through cuttings with
limited visibility. Locking of the electric points by track circuit
occupancy allows trams to approach at normal speed with the assurance that
no shunting is taking place from the other track.

The present small SLR fleet and running schedule makes it unlikely that two
trams would need to travel within sight of each other at speed.

If closer headways were needed with a larger SLR fleet after the Dulwich
Hill extension and the possible 'on street' routes in the near western
suburbs are in use , it would be a simple matter to incorporate a subsidiary
aspect on the station departure signals to alert drivers that another tram
was in the section but possibly out of sight. If two trams needed to travel
so close together at speed, wouldn't it be appropriate for them to be
coupled and fitted for multiple unit operation. That way, one driver only
would be needed.

Colour light signalling at the former Wynyard tramway station and tunnels
incorporated 'calling on' (CO) indications to allow closely following trams
to operate 'on sight' .

Sections of tram private right of way (PRW) in medians or open country such
as Sydney's former La Perouse line or Newcastle's former Wallsend line where
higher than normal speeds were attained (the latter with 'LP' trams having
maximum traction trucks) were generally reasonably straight with good
forward visibility.

Kensington Junction where the Coogee line diverged from the La Perouse line
was approached at higher than normal 'street' speeds and was fitted with a
facing point lock.

Other tramway facing points operated from signal boxes were not fitted with
facing point locks except for the crossovers in the tunnel north of Wynyard
station. These crossovers were air operated with facing point locks
controlled by track circuits. The track in these tunnels was ballasted to
sleeper level so that any derailment would have caused major disruption and
the need for lifting jacks in re-railing.

Noel Reed.

_____

From:TramsDownUnder@... [mailto:TramsDownUnder@yahoogroups.com]
On Behalf Of Ted Gay
Sent: Saturday, 4 February 2012 8:45 PM
To:TramsDownUnder@...
Subject: Re: [TramsDownUnder] Speed (OT)

My God how many times have I written on this group that a Variotram can do
80km/h on the Down in Glebe tunnel?

Ted

Ding ding

From: Matthew Geier matthew@...>
To:TramsDownUnder@...
Sent: Saturday, 4 February 2012 6:22 AM
Subject: Re: [TramsDownUnder] Speed (OT)

On 04/02/12 03:04, Fred Hearn wrote:
>

>

> Ok so thats 50m.p.h (80 kph) to the old trusty W

> Anyone driving the new trams want to better it???

>

They would have to disable the limiter first.

There might be places on the SLR where the ATP might allow such
speeds, but I don't know if such sections are long enough to allow the
tram to reach it.

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