Questions of Capacity and Quality of Service

Terry Flynn’s submission on the CSELR contains  calculations proving the proposed trams do not provide enough seating or crush capacity compared to existing buses. What is actually required for the future growth of public transport in the Eastern suburbs is double deck heavy rail. It delivers approximately 10 times the seating and crush capacity @ 20 trains per hour.

Trams_and_traffic_at_Railway_Square George StreetTerry’s claim is based on the following calculations and observations.

“The existing 891 bus service from Central to UNSW has 40 busses between 8 and 9 am. Each bus has at least 43 seats; therefore seating capacity exceeds 43 x 40 = 1720 seated passengers per hour.  The proposed tram has seating capacity per hour of 1600 for a 20 tram per hour frequency.

Considering my  calculations are based on only one bus route (891) using the smallest bus design, it is clear the current tram design is unable to provide the existing peak hour service to UNSW at the same comfort level with the proposed 20 trams per hour timetable.  It is unlikely this tram frequency can be significantly improved upon, as the system frequency is limited by traffic light timing and motor vehicle congestion.

There is no good reason why the new trams cannot have a greater seating capacity. The existing low floor Sydney trams has a seating capacity of 74 seats for a tram length of 28.3m. That gives 2.6 seats per metre length of tram. Assuming a 45m long new tram using the same seat to length ratio, the new trams could have a seating capacity of approximately 117 seats. This results in a seating capacity of 2340 seats per hour, an improvement on the existing 891 service but still not enough in the long term when you consider the trams replace more than one bus service and student numbers at UNSW are increasing.  I believe the trams need to be longer for UNSW services, and a 9 car 56m long tram might be a better option for the Central to UNSW service. Alternatively extra trams are purchased so that 2 trams coupled together run UNSW services during peak times.  Both solutions require all the tram stop platforms to be lengthened.

Buss frequency  1.67 min  891

40 /hour morning peak

Chassis: Mercedes-Benz O405
Built By: Pressed Metal Corporation
Length: 11.1 metres
Seating Capacity: 43, 47 (buses 3134, 3143, 3237), 49 (buses 3083, 3112, 3113)

4.4 seats/m.

Bus seating capacity 43 x 40 = 1720 / hour

Bus standing capacity 12 x 40 = 480 / hour

Chassis: Volvo B12BLEA

Built By: Volgren (Dandenong & Tomago)
Length: 17.965 metres
Seating Capacity:52
Fuel: Diesel – Euro 5
Years entered service: 2009 – 2011

2.9 seats / m.

Chassis: Volvo B12BLEA

Built By:Custom Coaches
Length: 17.96 metres
Seating Capacity: 64
Fuel: Diesel
Years entered service: 2005-2006

3.5 seats / m.

Sydney Variotram

Length  28.28m  Width  2.65m  Height  3.388mm  Weight  36,000kg  Seating Capacity  74  Standing Capacity  103  Total Passengers  223 ; 2.6 seats/m; Assuming 3 min frequency; Tram seating capacity 74 x 20 = 1480 / hour; Tram crush standing capacity 103 x 20 = 2060 / hour

New tram : 80 seats;  270 standing   total 300 passengers; 45m; 1.77 seats / m:Tram seating capacity 80 x 20 = 1600 / hour

Using same seat length ratio of  Sydney Vairotram 2.6 seats / m; Tram seating = 45 x 2.6 = 117 seats; Capacity = 117 x 20 = 2340 seats / hour; Crush  standing capacity 103 x 20 x 45/28.28 = 3277 ”

Terry Flynn  is a member of the Australian Railway Historical Society, international railway traveler and regular railway and bus user. 

(Photographs of Central Station and George Street in 1920s)

Advertisements