greencheeks77 said:
https://books.google.com.au/books?i...epage&q=unsafe overhanging shaft wall&f=false
Here is some basic info even though it is old the safety aspect of it should not be overlooked by any prospector (miner) never underestimate how much weight is on your wall and without any proper shoring, Without shoring (standard hole 2x4 feet) the walls must be plumb meaning dead straight up and down so when your in your hole looking up you don't want it to appear your standing in a funnel that's turned upside down..... Gold fever has struck many a prospectors and drift mining would of been the biggest taker of man..... there are an enormous amount of accidents that happened on the Australian gold fields that people hastily overlook..
https://www.worksafe.vic.gov.au/for...-for-builders-and-building-trades-contractors
1. Have all underground services been located?
Before digging starts, make sure you know the exact location of any underground electrical cables, gas lines, water, sewerage and telecommunications cables. Do not rely solely on site plans and drawings as these are sometimes not accurate or complete. Seek assistance from the local services and distribution companies.
2. Is earthmoving plant being used safely?
Check that plant operators are appropriately qualified. Look for qualifications endorsed with LL (for front-end loaders), LB (for front-end loader/backhoes), LS (for skid-steer loaders), LE (for excavators), LD (for draglines) or LZ (for dozers). Old-style pre-national certificates can also be used. Make the operators show you their qualifications and keep an on-site register. Make sure all earthmoving plant is properly maintained and fully serviceable. Check that operators are not undermining existing buildings or temporary structures such as scaffolds and falsework. Make sure spoil is being kept at least a half metre back from the edge of trenches and that earthmoving plant is a safe distance from the edge of excavations. Make sure unattended front-end loaders, backhoes and excavators are always left with the bucket fully lowered to the ground. When parked overnight alongside roads or on other public space, make sure earthmoving plant is locked up and barricaded with warning lamps to alert traffic.
3. Are workers protected from trench collapse?
Never allow workers to enter a trench or shaft which is greater than 1.5 metres deep unless it has been safely battered back, or it has been properly shored, or the workers are fully protected within a trench shield. Shoring should be positioned and fixed from above; never from below. All timber used in ground support should be at least F8 grade hardwood. Never use softwood because this can fail suddenly without warning, whereas hardwood will start to creak loudly when it is becoming overloaded, warning workers to leave the trench immediately. Make sure all workers in excavations always wear safety helmets.
4. Are confined space precautions needed?
Where there is any possibility of a hazardous atmosphere within an excavation, the extra precautions for entry into confined spaces must be put in place. (Examples and advice can be found in WorkSafe's publication Confined Spaces -- Shafts, Tunnels & Trenches.)
5. Are people safeguarded from falling into excavations?
Make sure trenches, shafts and excavations are properly barricaded, covered or isolated to prevent people falling into them. Whenever an excavation is to be left unattended, make sure it is secured to prevent children or other people from wandering into danger.
6. Is there safe access to trenches and shafts?
Never allow workers to climb up and down the soldier sets used in trench shoring, because they can loosen or damage the support system, triggering a trench collapse. Make sure industrial-grade portable ladders are used to gain access to the excavation floor.
7. Is someone else always present when a worker is below ground?
Never allow anyone to work alone in a trench or shaft. Make sure there is always another person close by who can provide help or get help if necessary.
8. Are open excavations being regularly inspected?
The condition of soil surrounding trenches and shafts can change quickly due to the soil drying out, changes in the water table or water saturation of the soil. Make sure the soil condition and the state of shoring, battering and trenches walls is frequently checked for signs of earth fretting, slipping, slumping or ground swelling. Where necessary, repair the excavation or strengthen the shoring system from above before allowing work below ground to continue.
Further Information
that's mainly to excavating a trench or being in lose unstable ground like clay
we go into solid rock so we look for hairline cracks recent slabbing folds and faults in the ground as well as joint planes in the rock shear zones witch are close to folds etc etc and we also get a long steel bar and tap the roof lightly if it sounds a hollow drum sound we don't normally go past that point as its hanged up and needs to be scaled off/down onto the floor there are other risks and dangers that we take not just cave ins
out main problems when exploring mines are bad air gases water filled adits and shafts and winzes in the floor of adits to a deeper level witch can't be seen that easy due to dirty water so we use a long steel pole and probe for any shafts in water filled adits we go into
and for dry adits if there's a lot of dirt on the floor and you can not see solid rock bottom how do you know there's not old boards under your feet covering a nice deep hole/shaft ? well simple you don't unless you get a slightly modified steel pole similar to the one mentioned above but with a small hammer on the end we simply wack the floor every foot or so if there's a drum hollow sound we dig up the dirt off the floor and 1 out of 20 times we find a boarded off shaft that connects to a deeper level of the mine
as for shoring ground up me and dean have been into so many we would have to put over 25000 skulls and lagging into almost 6000 different old mines all over Victoria it would be a massive job
these are the type of things you must acknowledge and understand and know about before even walking into a adit
some old mining terms
adit = tunnel
winze= shaft
skull = a prop wooden or steel used to support bad or broken ground usually in folded or faulted ground
lagging = wooden wedges to put in a prop to make it tight and stay in place
as I said before when I can afford a new camera I will point out all the dangers and the safest ways to explore an old mine without getting into any dangers
