Electronic BarriersPage last modified/checked: Monday, 7 October 2002
It wasn't until we combed over the many details of the electronic barriers did we realize just how much explanation and setting out was needed. This is perhaps ironic, given that they are physically the least common aspect of the Metcard system encountered by passengers. On the other hand, human interaction with them can provide an amusing show. This is more to do with the fault of the user, and to an extent, how the barriers are frequently set up to handle bi-directional flow. As a matter of interest, the worlds first automatic barrier gates were developed by London Transport during 1963-65. These were activated by special card tickets, initially with a form of magnetic ink bar code, then by tickets with a completely oxidised back. Important developments occurred in Chicago and the Philadelphia area over the remainder of that decade. In the latter case (PATCO), the worlds first fully automatic fare collection system and indeed rapid transit railway opened in the first months of 1969.
Melbourne's electronic barriers feature twin rectractable yellow plastic gates (or "paddles") and operate by sensor as each passenger passes through. The barriers are coded "036", and the gates are individually numbered, consecutively within each bank. Each gate is part of an individual barrier but linked to co-act with the opposing gate on the opposite barrier. This can sometimes lead to the unusual sight where a single gate remains retracted due to failure. Unlike many other systems, Melbourne's gates do not capture or retain any tickets, emphasising the multi-modal facet of the fare system.
Flinders St 24/1/1998, approximately one week after commissioning,
A wider gate (coded 037) is part of all automatic barrier installations and is provided for wheelchairs, prams and all non-Metcard ticket holders. This gate also incorporates an electrical counting unit (ECU) which beeps whenever someone passes through. It is permanently open, unless when attended by ticket checking staff, but otherwise is activated to validate tickets. From observation, the fact that they generally remain open makes this the entry/exit point for most people.
ID plate fitted to base of wider gate
Initially, some of the other normal width gates were locked open because of the large number of paper and card tickets still in use prior to the full roll-out of Metcard. When this was completed during the first half of 1998, they reverted to their intended use. The gates are bi-directional, (a green arrow appears at both ends) unless specifically set for single flow in which case a barred red circle is illuminated at the end through which you cannot enter or exit.
When the gates are locked open and de-activated, no indications are shown. During this phase, the electronic counters come on line and their "cheep" can clearly be heard as people pass through. When any ticket is rejected, it is returned through the intake slot. When the barriers are activated for bi-directional operation, the ticket intake slots are illuminated at both ends, however, the moment a passenger inserts their ticket, the slot at the opposing end de-activates and will not accept a ticket. During this process, the message "WAIT" is shown in the message display panel until the first person has passed completely through. This set up quickly sorts out the regulars from the stymied occasionals and in general can lead to congestion at a busy period.
The barriers have three distinct printing processes:
1: The initial validation process (common to all validating devices) whereby they calculate and print the expiry date for any ticket from a 2-hour to a yearly. On rail+2 tickets, this includes a 10-character station name.
To pass through, a passenger must insert their ticket into the intake slot. It is then pulled in, and, if valid, is returned through a slot on top of the barrier. To proceed through, the ticket must be removed; only then will the gates open. Passing the sensor beam immediately on the other side of the gates causes the gates to very quickly close behind the passenger. Unlike many other systems, the Melbourne gates will not allow a following person to insert their ticket until the barrier has completely processed the first passenger, thus the ability to speed passenger throughput has not been realised here. London Transport devised this method of speeding up the working of automatic fare gates during their early trials as it minimises gate cycles and also reduces component wear.
OK UNTIL .... the expiry date of the particular ticket will be shown CHECKING during the initail verification of the magnetic strip on a Metcard NOT VALIDATED the ticket was not validated upon first entry to the system and thus the barrier will not accept it to exit the system EXPIRED the expiry date or time has elepsed for that particular ticket RE-TRY the ticket was inserted upside down, wrong-way around or is damaged TAKE TKT the ticket is valid and waiting to be removed from the slot PASSBACK this term identifies a system safeguard developed to lock out the potential for anyone to hand back their valid ticket to another person who attempts to reuse it to enter the paid area within a certain time frame OK CSE as mentioned in the introductory section to employee touchcards, passenger service employees hold a special plastic card purely for activating automatic barriers. This is at their own discretion, but usually when a passenger needs assistance getting through for a variety of reasons. OK TRIPS LEFT 0 shown when a rail+2 (a single journey ticket)is inserted (0 = zero) NO TRIPS LEFT shown when an expired rail+2 is inserted WAIT as explained above INVALID TICKET when a short trip (tram only) is presented for use WRONG ZONE the ticket is not valid for the zone where the passenger is attempting to enter or exit
A permanent fixture are the overhead signs identifying Metcard barriers from the wider "all other tickets" gate. As part of the initial education process, large "Metcard" stickers were placed on the ground approaching all gated barriers, together with stand and wall-mounted posters explaining and illustrating the validation process.
It was always intended to include electronic barriers as part of the automated ticketing system. However, they were the last aspect to appear, as it was not felt wise to bring them into use until the Metcard rollout had covered a reasonable portion of the rail system. Initially, wooden mock up or "dummy" gates were installed in the pedestrian subway at Spencer St station in early April 1996, closely followed by Flinders St. Concurrently, mobile dummy gates were trialled at Caulfield, Dandenong, Ringwood, Blackburn and Oakleigh. This was done to best assess the positioning of the future bank of permanent, active barriers. At the latter two stations, it was eventually decided that free standing validators were better suited. At Flinders St, lenghty trials of dummy gate positioning were undertaken within the Elizabeth St pedestrian subway as it was felt that the actual Elizabeth St entrance alone could not be expected to handle the sheer volume of people. These dummy gates were soon fitted with electronic counting units to help determine how many barriers might be needed. Ultimately, intermediate single barriers were provided as well as a single wide barrier at the Southbank end - the only example of this arrangement on the system.
Barriers being installed at Camberwell, 10th June 1997
Several features need to be pointed out in this photo. Fixed to the wall on the left are two of the temporary validators that were provided at a number of locations prior to the installation of electronic barriers so that people had a means of validating their tickets. At some locations, though long since de-activated, these validators still have not been removed. Note also that they are of a different design from those developed and fitted in buses and trams; the smartcard target is not defined, and the LED screen is incorporated in the face rather than at top left. Just visible also is the white sticker placed over the intake slot on the (removed) barrier fascia. The wording on these stickers indicated that the barriers were installed and awaiting commissioning prior to public use.
FURTHER CHANGES etc
Several more events need to be explained to bring the story of the electronic barriers up to date.
2000 "Barrier Closure"
Some of the curious reminders:
Click for 70k image.