design of such steps and a suitable handrail provided. It is sometimes possible to reduce the number of steps by taking advantage of falling ground or artificial changes of level.
Communal containers
are some-
times placed in a room or enclosure in the block of dwellings or adjacent to it, but more commonly they stand some distance away, thus giving cause for complaint from users that they have to go out in the open to deposit their refuse.
In the user study 89% expressed general satisfaction with communal containers, though 38% noticed smell from the containers and 34% reported some difficulty in their use, such as the height or the size of the opening or stiffness or heaviness of the lid.
Chutes
Chutes have openings providing for insertion of refuse at upper floor levels and discharge into a container at ground level. Chutes are general- ly of 15 in. internal diameter, but 12 in. chutes have been installed in the past and are still in use, while the trend now is to use 18 in. Salt- glazed ware pipes (e.g. to B.S. 65 or B.S. 540) are generally used, but spun concrete or asbestos cement pipes are also used. The entry points are fitted with metal hoppers which are designed to facilitate the insertion of refuse in the chute and to prevent the escape of dust and smell both during use and when closed. The containers are most commonly of
of the type already described for use as communal con- tainers, but other shapes and sizes are employed. The requirements for chute installations are set out in B.S. 1703, 'Refuse chutes for multi-storey buildings'.
Chute disposal is open to some of the objections already mentioned in connection with dustbins and com- munal containers, e.g. smell, noise and unsuitable position. In a user study 60% of tenants could hear others using the chutes (though only 21% considered this a nuisance) and 35% reported smell from chutes. Twelve per cent thought the position of the hopper nearest to their dwelling unsatisfactory either too near because of smell, dust and noise, or too far because of exposure, as on access balconies. Chutes are
136
also subject to blockages, which may be troublesome to clear and if not cleared promptly increase the likeli· hood of dirt and smell within the building. As would be expected, blockages occur more frequently with the smaller diameter chutes than with the larger. There is a further risk of spread of fire or smoke from fire through chutes, making it necessary for hoppers to be placed in open positions, though at high levels these
be exces- sively exposed to wind and rain.
may
It is sometimes suggested that, by reducing the size of the hopper open- ing, blockages will be reduced by excluding larger articles. Most of the hoppers seen in the survey had openings between 100 and 185 in2 but in view of the number of other factors which could cause blockages was slightly less with small hoppers. but in view of the number of other factors which could cause blockages it is not thought that this is a signi- ficant result. Larger hoppers were on the other hand understandably preferred by housewives for con- venience in use.
The proportion of tenants express- ing general satisfaction with chute disposal was 92%, thought 46% con- sidered improvements were necessary in their installations. Half of these comments concerned hopper design, larger hoppers being generally de- sired. Others related to the need for improved cleanliness and prevention of smell.
The Garchey system
The Garchey system is of French origin, but is the subject of British patents. In the examples examined in this study, domestic refuse was waterborne through pipes to a local disposal station where it was dried and burnt. The disposal point for the housewife was an enlarged waste outlet in the kitchen sink, which dis charged into a receptacle (the 're- ceiver') underneath, so that refuse deposited through the outlet was im- mersed in waste water from the sink. Periodically the user discharg ed the contents of the receiver through a trapped outlet at its base, and the solid refuse was flushed by the flow of water down a vertical stack into an underground collection chamber, one of several distributed throughout the site. After
a period of settlement the contents of these collection chambers were drawn by suction to the disposal station, where liquid was drained
off to the sewer. The solid matter, after being dried by centrifugal ac- tion, was destroyed in a gas-fired in- cinerator.
The outlet at the base of the re- ceiver was stopped by a long-handled plug or plunger' which the user simply lifted by hand in order to discharge the contents. The entry of outsize articles to the system was partly prevented by a gauge in the mouth of the receiver. In addition, users were asked to put down only articles which, besides being less than the gauge width, did not ex- ceed 8 in. in length
The manufacturers did not sug. of gest any restrictions on the type refuse put through the system only the size of individual items was re- fre- stricted. They recommended quent emptying of the receiver, but warned on grounds of economy against excessive use of clean water for flushing. The intention was that waste water from the sink should accumulate in the receiver with the solid refuse and that clean water if used at all should be added only for topping-up before discharge.
The user study included the six Garchey installations then in opera- tion in Britain. The proportion of users generally satisfied with the sys-
was
tem was 95% for 97% if one scheme where the installation was undergoing a general overhaul, is omitted.) There was some variation between schemes in the extent to which the Garchey installation used for the disposal of the main items of refuse, and this was partly due to the restrictions placed on the use of the system by some of the local authorities concerned. At some schemes tenants were discouraged from putting specified items of fuse, such as bottles and tins ог cartons and waste paper, down the Garchey, whereas at others these ar ticles were disposed of, apparently successfully, in this way.
re-
Twenty-seven per cent of tenants complained of mess or smell in the sink, and 32% mentioned the dif- ficulty of cleaning the receiver, con- sidering it the main disadvantage of the system. This did not, however, affect their conclusion that on the
THE HONG KONG & FAR EAST BUILDER - VOLUME 18, NUMBER 5