A NEW DESIGN OF DOUBLE-DECK BUS.
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A Suggested Type of Six-wheeler of Large Seating Capacity Having Several Interesting Features.
TIC view of recent developments in _L the production of large-capacity double-deck buses in which six-wheeled chassis are employed, a description of a new design in which novel features are incorporated will prove of interest. The design has been prepared, primarily, to show the application of a novel arrangement of entrances and exits, which is the subject of a patent. The arrangement provides a separate entrance and exit for both decks, thus enabling delays to be reduced at stopping places when interchanging it number of passengers and giving greater comfort and convenience to passengers, apart from resulting in higher average speeds being maintained.
To secure these advantages to the full, two stairways and two doublewidth openings are required in the side of the bus. In order, however, to
avoid a serious loss of seating capacity during the rush hours it is proposed to close one of the stairways temporarily, by a trap-door, thus allowing collapsable seat g to be brought into ser vice above it. Furthermore, the stairway near the front of the bus will pre ferably be of the straight type, and it may. therefore, be easily arranged to turn into a vertical position during rush hours, thus allowing space for additional seats on the lower deck.
The result of this construction is that a separate exit may be provided for both decks of, a double-deck bus during the greater part of the day, with a loss of but two or three seats during rush periods, as compared with the conventional type of bus, whilst there is still a special exit for the lower deck.
A separate exit for the upper deck has particular value on large-capacity top-covered buses in city service, because of the impossibility of passing on the stairway and the greater capacity of the upper deck.
Both entrance and exit being of double width, stops for picking up passengers or setting theni down only involvle no greater delay than with present types of bus having a double width rear platform, whilst appreci able time-saving is possible both when picking-up and setting down at stop ping places, particularly as the Choking of gangways and platform, so apparent at the present time, is avoided.
The type of bus shown in the accompanying drawings has the conventional arrangement of rear platform, a second straight stairway near the front, pivoted at the foot to enable it to be pulled into a vertical position, a trap door over this stairway and collapsable spring, tip-up seats over the trap-door
fixed to the front bulkhead. These seats may be used by passengers when all others on the lower deck are occnpied, the doorway at that side then
being closed, upper and lower-deck passengers using the other doorway.
When the maximum seating capacity is required, the conductor lowers the Stairway guard rail on the upper deck just over the trap-door, descends the stairway, closing trap-door behind, folds in hand-rail and pulls stairway into its vertical position. Passengers may then take four or five additional seats—three or four tip-up seats On the upper and two on the lower deck. After the rush-hour period has passed these operations are performed in the reverse order. This routine may be carried out quickly, easily and safely.
The folding stairway illustrated allows the trap-door to be closed before it is moved, the vertical and intermediate positions being shown dotted, and, with a simple arrangement of interlocks, it ensures absolute safety at all times. An interlocking bar fixed to one of the upper-deck seats interlocks the trap-door, guard-rail and seats.
It does not follow that because the separate exit for the upper deck is closed during the rush-hour period, this facility is lost when most desirable, as traffic is very much of a unidirectional character at this time, i.e., cityward or homeward, and, generally, it is thought that this loss will not be appreciable.
It will be apparent that there are several alternative arrangements possible, particularly with regard to the disposition of the seats. Thus, if a number of rearward-facing seats is considered undesirable, this may be altered without much difficulty. Further, the front stairway need not be movable, although it is easy to arrange it so and thus gain two more seats.
If desired, the entrance may be at the front, but it is believed that this is best at the rear, because (I) boarding passengers are not confused by the changed routine, (2) the driver can see boarding passengers in mirror and alighting passengers at front and need not wait for the conductor's signal, (3) a low stepless platform is more useful for boarding, and (4) boarding while the vehicle is in motion is a convenience and is safer when carried out on a rear platform.
Public acceptance and appreciation of the new arrangement would be largely dependent on the provision of a convenient arrangement of front doors and operating mechanism for them. Whilst recognising the possibilities and advantages of pneumatic mechanisms, it is believed that a simple arrangement of manual mechanism would suffice. Thus the doors might be opened by passengers themselves by a straight pull on a carefully placed handle on the folding door. They might be closed by the driver through .a pedal, a false tread on the step locking the doors to prevent premature closing.
It is intended that the front stairway would be painted or panelled to con: form with the interior decoration, so that it would not be obtrusive and objectionable. Further, the back of the stairway could he fitted with a window.
It is estimated that the cost of the double front exit would be justified by
a time saving of second per mile only. There is little doubt that with increasing competition and traffic congestion, larger buses, higher average speeds, and fewer stops the advantages of s6parate exits arc 'of increasing value.
Apart from the front-exit feature
just described, the design illustrated may have some interest as showing what may be the ultimate limit of seating capacity for a bus of 30 ft. overall length. As will be seen, the upper deck has been brought forward so far as possible. The writer has not seen any previous design or construction in which a top-covered upper deck is brought forward in conjunction with a forward-control arrangement.
This would appear to be quite a logical development, as top-covered buses now provide an ample factor of safety against overturning, and the method does not reduce the present amount of headroom given to the driver. In the same way that the upper deck of the tramcar has been brought forward in the past, so may bus builders adopt this construction to secure the maximum seating capacity within the principal dimensions. Double-deck buses of this length are now operating in provincial cities.
The bus shown provides a maximum of SO seats, with 72 seats in non-rush hours, allowing two seats on the rear platform under the stairway and 2 ft. 3 ins, between seats, which is quite a usual and fairly generous spacing for city buses. Most of thc dimensions are usual apd the front stairway has treads of 7 ins, and rises of 10-i ins., giving a stairway no steeper than many now in public service. .
The ratio of seating of lower to upper deck is as 7 to 9. Whilst the safety of a bus having this proportion of lower to upper-deck seats has yet to be established, the remarkable results of tilting tests on top-covered buses suggests that this ratio may still allow a satisfactory margin of _safety under the varying conditions of loading, etc.
The special front-exit feature is'not, of course, limited to exceptionally large buses, and may be applied with ad vantage to smaller vehicles in heavy traffic.
The design of this type of body hag hen evalved by Mr. Henry Watson, of Wallington, surrey. •