Cleaning Out Placer Deposits

All the work and homework that is actually put into finding out about how dredges work is time consuming but when it comes down to it dredging is not a complicated thing. However, it does help to understand how they function on the inside and the purpose of every part of the machine etc. Another thing, dredging may be simple but it does require of some effort but most of it has to do with bracing your body against the current. Moving the suction nozzle around does not consist of a lot of work and the good thing is that it does not weigh a lot when it is under the water.

After you have the gravel to get flowing through the sluice there are just a few basic rules that need to be taken into consideration and learned about. Make sure to not forget about the rules that you have been told about following the pattern of suction on the stream bed. After you have started cleaning out a pocket placer you will very quickly find out that the pattern the suction nozzle makes is going to be decided on by the type of pocket or area you are going to be doing placering in. if you are going to be dredging right across a stream bed, like you would need to do in the case of three anchorings, you will most likely be advancing in a half circle if the stream current is filling up your hollow spaces rapidly. However if the water is not moving very fast and the hole you have dredged is not filling up quickly it is possible you will be able to remove overburden all the way across to which you can then switch over to another kind of suction nozzle and clean up the gravel you are more interested in getting to close to the bedrock.

There are basically two different types of ways to clean out placer deposits. One way is the rapid descent that is normally used in pocket placers and which is often done in bigger ones when flow sand fills the hole up rapidly. When this type of dredging is done you can dig a round area that is around three times larger than the area you are thinking about dredging at the bottom. This is not an easy thing to estimate since the proportion of the surface excavation to the bedrock excavation will be based on how quickly the hole is filling in and how deep the excavation is going to be. The main idea is to dredge to bedrock or to the bottom of a pocket placer before the hole fills up with gravel once again.

Another type of way to clean out placer deposits is by excavating big areas of overburden and this is in most cases done with a better capacity suction nozzle and then return with a better suction nozzle as the depth gets close to the bedrock. This type of dredging is usually used by divers and due to the fact that it is quite a time consuming type of dredging, it is normally only done in operations that are bigger. There are not any predetermined rules that can be said since the size and type of excavation largely has to do and depends on the overburden, the stream current as well as the type of gravel and a lot of other physical factors that may be restrictive, each situation varies.