For you digger or excavator experts

[I'm getting on a bit]

Hit the leccy and it's bye bye Adrian

 

[angellonewolf]

what thers no rcd on the line (sniggers)

 

[8ob]

Take the teeth off the bucket and go nice and slowly

Bob

 

[AdrianH]

Well I have hit a few things! Mostly Kerb-stones, bits of roof tiles, a bit of blue tubing, (empty) Bricks, and clay. I can well understand why the garden does not drain and becomes waterlogged and this is all at above 18 inches. I think the back garden was basically a builders dump area!

I will post a picture of the area soon, just to try and give an idea of the thoughts so far.

Adrian

 

[I'm getting on a bit]

what thers no rcd on the line (sniggers)

You don't have rcd's on main services guffaws

 

[AdrianH]

Sorry for the hand drawn lines


Got my colours all wrong but The green line is the water into the house.

The red and brown lines are gas and electricity going into the meters, not sure what side the come in from the road yet, as there are no covers to look under, but the meters are that corner of the house.
The blue is the path of rainwater run off and yellow are waste water from loo's and sinks, included there are also some from the house next to the garage as I know some drains come from there to the drive at the side of the house and possibly under my garage. We have 4 man holes in the paved area and two where the blue car is parked.

From the drive area it appears to go out to the road where the main sewer should be. Now to me all mains services should go from the roads to the houses and waste to the roads from the houses, none should be criss crossing our gardens.

Next couple of pics are from an upstairs bedroom window looking out5 over my postage stamp back garden that is a swamp.


In the first picture is the start of a shallow trench under the lighter shade ply. In that corner previously was a 26 year old tree that was removed together with several large bushes as they took light from a neighbour. It also means no tree roots to soak the water, more wetness!

The plan is to dig a simple land drain, fit geo textile, gravel, perforated pipe more gravel and then a layer of top soil, around the top of our grassed area, down in the same grass area by the path you see, through the flower bed and then across in front of the greenhouse to a sort of man made well by the white bin you see, in front of the greenhouse on the corner of the garage. In the well/hole is a rain water grid from the garage and the basic idea is to let any land water drain into there, other wise I am having to go into the paved area and deeper still to get into the main drain system.

Now the part I do not know yet is from the corner of the house to the nearest corner on the garage is a buried armoured mains cable to supply the garage, I believe it will be there in my last section of dig.

As you can see the back is several heights coming down to the house, we are also the bottom of a row of houses so we have run off from those above.

As mentioned we have removed trees where we are presently digging next to, the total length of trench is in the region of 18 meters.

I am trying to get my hands on a CAT and Genny so I can find my mains to the garage, I may even try to figure the path the mains uses from the road to the house.

So I am not trying to excavate any public paved or road area. The phone line is also from the front of the house to the road. We contacted council to ask for any plans and basically got told no but should be below 2 ft?

That I guess will be ground level of the house, I do not expect to find services where I am digging, but I am looking out for tell tales as I go, but with the rubble I am digging out who knows what I will find, I was expecting parts of a body after I dug up some clothing?????

Adrian

 

[I'm getting on a bit]

This is where your wrong.

When I did my sons drive, the leccy came from next doors then a 90 degree turn into the house.

I'm not a wimp, I dug it out by hand although I did admit defeat when it came to two tree roots and the soak away.

6mtrs x 6mtrs

 

[WorkshopChris]

what thers no rcd on the line (sniggers)

There are more injuries caused from damaged cables shortly after the event.
Cable is damaged = big flash and bang then the sparks stop, driver get out and get closer to see what he hit.
In the meantime the auto rest circuit breaker or auto fuse changer has re set and re energised the line. Depending on the fault the cable may either re energise and stay live or ark again. This process may repeat upto 3 times.
It is often this re energising that may get people as once any initial flash is seen they presume it is now safe.

 

[eLuSiVeMiTe]

Seen a few pipes go. Wasn't on site for the gas main someone got.
Previous employer pulled a tree over with a JCB unknown to him an armoured cable came with it. Took the substation out. Same job he nearly put the digger in an old cesspit 3mx4mx2m deep. Needless to say I didn't hang around for long and found a new employer. Hit a water main once myself came through the neighbours fence and had no business being there. Always keep a pipe clamp handy thankfully.

 

[8ob]

Seen a few pipes go. Wasn't on site for the gas main someone got.
Previous employer pulled a tree over with a JCB unknown to him an armoured cable came with it. Took the substation out. Same job he nearly put the digger in an old cesspit 3mx4mx2m deep. Needless to say I didn't hang around for long and found a new employer. Hit a water main once myself came through the neighbours fence and had no business being there. Always keep a pipe clamp handy thankfully.

Squeeze off is a must, MDPE services are rarely where they are supposed to be or at the correct depth. Between the diggers, trenchers and stump grinders we seem to have unearthed our share.

Dinky one for domestic stuff





And the big guns for when things go very badly, and they have

 

[eLuSiVeMiTe]

Never found a mains that big thankfully. Gonna be a big puddle.

 

[slim_boy_fat]

I think the back garden was basically a builders dump area!

All too common - it'll be the spoil from when they dug the foundations.

 

[slim_boy_fat]

There are more injuries caused from damaged cables shortly after the event.
Cable is damaged = big flash and bang then the sparks stop, driver get out and get closer to see what he hit.
In the meantime the auto rest circuit breaker or auto fuse changer has re set and re energised the line. Depending on the fault the cable may either re energise and stay live or ark again. This process may repeat upto 3 times.
It is often this re energising that may get people as once any initial flash is seen they presume it is now safe.

If the ground is as wet as @AdrianH seems to indicate, what would the effect of severing a live supply which would then effectively be lying in water?
Would the operator be in any danger when he got off the digger, or would the supply go into an on/off 'loop'?

Genuine question, I don't like messing with stuff I can't see..........

 

[WorkshopChris]

If the ground is as wet as @AdrianH seems to indicate, what would the effect of severing a live supply which would then effectively be lying in water?
Would the operator be in any danger when he got off the digger, or would the supply go into an on/off 'loop'?

Genuine question, I don't like messing with stuff I can't see..........

All depends how it is damaged and if it is normal LV or HV.
HV will often try to re set as often the arc has enough force to clear the original fault.(Basically the copper or ally vaporise until it disappears back into the insulation.) In water it would depend on any earthing to carry the fault current.
Not something i ever want to see.
LV can clear if self in a phase to phase fault. in water it will normally arc until the fuses give in.
Not saying you would be ok but i would say the risk from fire or burning is still higher than electrocution.

This video shows the result of a possible re supply to a fault. you can see the pavement is already burnt from the 1st blast and burns again when powered up again.
The guys from the DNO have my uppermost respect, i know its all about safe systems and training but i would not do the job they do.
I have personally seen a guy with full frontal burns from a flash over on a 500a busbar. At the time auto pilot kicks in you make sure the ambulance is called,make sure the site is safe, 1st aid to cool the skin. Its after it hits home, i could smell burnt flesh for the rest of the day and i am sure it must be psychological but a good few days later every now and then the small was back just briefly.
I have a fault on a buried cable i am tracing now cant find it with testing but its pulling a load after heavy rain.
I have worked on a few buried cables on site even though i know both ends are bonded down to earth and locked off i always work as if the supply is live.

 

[Robotstar5]

I have worked on a few buried cables on site even though i know both ends are bonded down to earth and locked off i always work as if the supply is live.

Just spike them first.

 

[AdrianH]

My word your a cheery lot!

Adrian

 

[WorkshopChris]

My word your a cheery lot!

Adrian

Unless you live next to the substation you will be fine.
Looks like a nice machine, wish i had got one when we started ground works at home.

 

[slim_boy_fat]

All depends how it is damaged and if it is normal LV or HV.
HV will often try to re set as often the arc has enough force to clear the original fault.(Basically the copper or ally vaporise until it disappears back into the insulation.) In water it would depend on any earthing to carry the fault current.
Not something i ever want to see.
LV can clear if self in a phase to phase fault. in water it will normally arc until the fuses give in.
Not saying you would be ok but i would say the risk from fire or burning is still higher than electrocution.

This video shows the result of a possible re supply to a fault. you can see the pavement is already burnt from the 1st blast and burns again when powered up again.
The guys from the DNO have my uppermost respect, i know its all about safe systems and training but i would not do the job they do.
I have personally seen a guy with full frontal burns from a flash over on a 500a busbar. At the time auto pilot kicks in you make sure the ambulance is called,make sure the site is safe, 1st aid to cool the skin. Its after it hits home, i could smell burnt flesh for the rest of the day and i am sure it must be psychological but a good few days later every now and then the small was back just briefly.
I have a fault on a buried cable i am tracing now cant find it with testing but its pulling a load after heavy rain.
I have worked on a few buried cables on site even though i know both ends are bonded down to earth and locked off i always work as if the supply is live.

Holy Moly!! I'd definitely be hand digging in the area(s) I knew to be near any supply cables after seeing that. Thanks for posting.

 

[WorkshopChris]

Holy Moly!! I'd definitely be hand digging in the area(s) I knew to be near any supply cables after seeing that. Thanks for posting.

If you want to be double safe they make shovels with composite ends and insulated fibreglass handles.

 

[slim_boy_fat]

If you want to be double safe they make shovels with composite ends and insulated fibreglass handles.

Better still, leave the digging to someone else.