This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol6", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
With regard to the drainage proper, the client may have his special fancy as to whether he will have it on the surface or underground. It really matters little so long as the systems are efficiently laid. If underground drains are used a horse-pot of some description is necessary, of which that shown in Fig. 22 is a good example, with bucket to receive solids, and inspection eye quite apart from trap itself. The drainage from one or more stalls (Fig. 23) is conducted by a channel to this pot, whence it goes to an inspection pit or special trap outside. A special drain-pot for outside purposes (Fig. 24) is made by Messrs. Young & Co. It is intended chiefly for systems where all inside drain-pots are dispensed with. The illustration practically explains itself. Inspection to stable gutter is obtained without removing the bucket, as is also inspection to main drain. The laws of ventilation should be applied as for house drainage, and a foul-air shaft provided where an inspection pit is used (see Volume II.).
The channel used to lead to the horse-pot or direct to outside trap may be entirely open, such as that made by the St. Pancras Ironwork Company (Fig. 25), which is made of wrought iron and is firmly fixed into the concrete bed by means of the lugs underneath. These open channels may be used in conjunction with horse-pots, or they may be carried as surface drains till they reach the exterior wall of stable, through which an opening has to be made, protected by a flap valve; and here the contents are discharged over an open pit or trap. In many cases the drainage channels, whether in connection with horse-pots or not, are covered over with a perforated grating, the cover being easily taken off for cleansing purposes, and put on so as to afford a level walk and at the same time satisfactorily hiding all drainage. Fig. 26 shows a channel which is so made that sufficient fall is given to take away urine, whilst at the same time allowing the stall to be kept almost level, the only fall being from each side towards the gutter in the centre. This is a decided advantage. These channel gutters, whether open or otherwise, are run to about 4 feet from stall head, unless water is supplied to and wasted from the water feeding pot - when the channel should be continued to receive waste pipes, which will prove effective in swilling the channel. Fig. 27 shows a cast-iron perforated cover top to a concrete or brick channel as made by Messrs. Musgrave & Co. The wrought-iron pieces which carry the cover are firmly bedded in the concrete. Another form is shown in Fig. 28. In loose-boxes, where horse-pots are used, it is customary to place them in the centre and to drain the floor towards them, as shown in Fig. 29, or these channels may be placed anglewise as desired.
Fig. 26. Youngs Surface Gutter.