be approved by the Board but in no case to be less than six inches. It is understood that this limitation of size refers to main house-drains and not to branches from such main, but it is very desirable the point should be clearly and distinctly settled.
10. The Committee also wish to call attention to the last three lines of section 47 of the Ordinance and recommend that the following words be added:- except in special cases where there is no other readily available means of bringing down such waste-pipe or down-pipe, and when the Board has given its consent in writing to such being done.
11. The Committee deem it desirable to append to this Report copies of the letters they have received from Architects and Engineers in reply to the communications the Committee addressed to them.
(Signed),
N. J. EDE.
J. J. FRANCIS.
J. D. HUMPHREYS.
S. BROWN.
Page 73
DRAFT OF AMENDED DRAINAGE BYE-LAWS.
Preliminary Explanatory Notes.
4. The following notes convey, in general terms, the principles that should guide the design and construction of house-drains. Before proceeding to lay down in detail the instructions which should be attended to, in order to apply the same satisfactorily; it must be observed that no end of instructions can possibly embrace every case that will occur. It must be remembered that no system of house-drainage that has yet been devised, or probably will ever be devised, does away with the necessity for care in use. The real remedy for the inconveniences which are too often experienced from house-drains lies, not in any elaboration of appliances, but in careful construction, careful use, and a reasonably liberal water supply. Without the co-operation of the public, the Sanitary Authority is almost powerless to effect improvement. It is therefore to be hoped that the public will assist, by insisting on good construction and the proper use of house-drains.
B. The object of a house-drain is to carry off, from the dwelling to the street-sewer, water fouled by use, together with all the solid or semi-solid refuse which is usually associated therewith, such as excrement of men or domestic animals, refuse from cooking and the like; in short, the foul liquid usually known as sewage.
C. The house-drain must be self-cleansing. The sewage as produced in the daily life of the inmates, must flow through the drain with a current sufficiently rapid to sweep along with it all suspended matter, so that no permanent deposit can take place. A drain in which deposit takes place, is a cesspool in disguise, from which offensive emanations find their way into the dwelling; and from which putrid sewage flows into the street-sewers, making them exceedingly offensive. A badly constructed or badly kept house-drain is, therefore, not only a source of danger to the inmates of the house that it drains, but a public nuisance also. Unless house-drains are well made and properly used, no system of street-sewers, however perfect, can work in a satisfactory manner.
D. Water being the agent which cleanses the house-drains, its liberal use by the inmates of the dwelling, is essential to the proper maintenance of house-drains. The sewage must be well diluted. Nevertheless, the quantity of water necessary for the proper cleansing of house-drains, is not excessive. The water normally used by the inmates of a dwelling for washing and cooking, is sufficient for this purpose, provided that it is readily obtainable at all times, either in the dwelling, or in close proximity thereto.
E. The principal point to be attended to in the design of house-drains, is so to arrange matters that the sewage, as produced, shall flow through them in the most rapid current practicable; so that all suspended matter shall be swept away at once and completely.
F. The speed of a stream flowing through a pipe or channel, of given size and shape, depends upon the following conditions:-
(a.) The inclination of the channel.
(b.) The smoothness of its surface.
(c.) The volume of the stream.
The steeper the slope and the smoother the sides of the channel, the swifter will be the current. The greater the volume of the stream, inclination being the same, the greater the speed. Thus; if a 12" and a 3" pipe have the same inclination the velocity in the 12" pipe would be about twice as great as in the 3" pipe, provided that both were half full. But to fill the two pipes to this extent, the quantity of water passing through the 12" pipe, would be about thirty-two times that passing through the 3" pipe. But if the same quantity flowed through both pipes, then the current in the 3" pipe, being more concentrated, would flow more rapidly than that in the partially filled, 12" pipe.
G. These considerations would lead to the conclusion that the best size, to be used for any house-drain, would be that which would just suffice to carry off the sewage with the pipe not less than half full. Within certain limitations, this is the case.
H. In the case of street-sewers draining large districts, from which the flow of sewage is comparatively regular and capable of estimation, the proper size of sewer may be calculated with some approach to precision. In the case of house-drains, however, such precision is impracticable. The rate of flow is irregular and the quantity of sewage depends upon the habits of the inmates. Were the size of a house-drain calculated to carry off even a most liberal water supply, which is,
Page 78
be approved by the Board but in no case to be less than six inches. It is understood that this limitation of size refers to main house-drains and not to branches from such main, but it is very desirable the point should be clearly and distinctly settled.
10. The Committee also wish to call attention to the last three lines of sec- tion 47 of the Ordinance and recommend that the following words be added:- except in special cases where there is no other readily available means of bring- ing down such waste-pipe or down-pipe, and when the Board has given its consent in writing to such being done."
11.-The Committee deem it desirable to append to this Report copies of the letters they have received from Architects and Engineers in reply to the com- munications the Committee addressed to them.
(Signed),
N. J. EDE.
J. J. FRANCIS.
J. D. HUMPHREYS.
73
S. BROWN.
1:
})
DRAFT OF AMENDED DRAINAGE BYE-LAWS.
78
Preliminary Explanatory Notes.
4. The following notes convey, in general terus, the principles that should guide the design and construction of house-drains. Before proceeding to lay down in detail the instructions which should be attended to, in order to apply the same satisfactorily; it must be observed that no ende of instructions can possibly embrace every case that will occur. It must be remembered that no system of house-drainage that has yet been devised, or probably will ever be devised, docs away with the necessity for care in use. The real remedy for the inconveniences which are too often experienced from house-drains lies, not in any elaboration of appliances, but in curaful construction, careful use, and a reasonably liberal water supply. Without the co-operation of the public, the Sanitary Authority is almost powerless to effect improvement. It is therefore to be hoped that the public will assist, by insisting on good construction and the proper use of house-drains.
B. The object of a house-drain is to carry off, from the dwelling to the street-sower, water fouled by use, together with all the solid or semi-solid refuse which is usually associated therewith, such as excrement of men or domestic animals, refuse from cooking and the like; in short, the foul liquid usually known as sewage.
C. The house-drain must be self-cleansing." The sewage as produced in the daily life of the inmates, must flow through the drain with a current sufficiently rapid to sweep along with it all suspended matter, so that no pormanent deposit can take place. A drain in which deposit takes place, is a cesspool in disguise, from which offensive emauations find their way into the dwelling; and from which putrid sewage flows into the street-sewers, making them exceedingly offensive. A badly constructed or badly kept house-drain is, therefore, not only a source of danger to the inmates of the house that it drains, but a public nuisance also. Unless house-draius are well made and properly used, no system of street-sewers, however perfect, can work in a satisfactory manner.
D. Water being the agent which cleanses the house-drains, its liberal use by the inmates of the dwelling, is essential to the proper maintenance of house-drains. The sewage must be well diluted. Nevertheless the quantity of water necessary for the proper cleansing of house-drains, is not excessive. The water normally used by the inmates of a dwelling for washing and cooking, is sufficient for this purpose, provided that it is readily obtainable at all times, either in the dwelling, or in close proximity thereto.
E. The principal point to be attended to in the design of bouse-drains, is so to arrange matters thut the sewage, as produced, shall flow through them in the most rapid current practicable; so that all suspended matter shall be swept away at once and completely.
F. The speed of a stream flowing through a pipe or channel, of given size and shape, depends upon the following conditions:--
(a.) The inclination of the channel.
(6.) The smoothness of its surface.
1)
current.
(c.) The volume of the stream,
The steeper the slope and the smoother the sides of the channel, the swiftor will be the The greater the volume of the stream, inclination being the same, the greater the speed. Thus; if a 12" and a 3" pipe have the same inclination the velocity in the 12" pipe would be about twice as great as in the 3" pipe, provided that both were half full. But to fill the two pipes to this extent, the quantity of water passing through the 12" pipe, would be about thirty-two times that passing through the 3 pipe. But if the same quantity flowed through both pipes, then the current in the 3" pipe, being more concentrated, would flow more rapidly thau that in the partially filled, 12" pipe.
G. These considerations would lead to the conclusion that the best size, to be used for any house-drain, would be that which would just suffice to carry off the sewage with the pipe not less than half full. Within certain limitations, this is the case.
H. In the case of street-sewers draining large districts, from which the flow of sewage is comparatively regular and capable of estimation, the proper size of sewer may be calculated with some approach to precision. In the case of house-drains, however, such precision is impracticable. The rate of flow is irregular and the quantity of sewage depends upon the habits of the inmates. Were the size of a house-drain calulated to marry off even a most liberal water supply, which is,
No comments yet.
Private notes are available after approval.