Richard-

Please send me an email off list at [log in to unmask] and I will send you what I have in the way of pictures of the process. Paul Avery and I dealt with three wells at the Confederate guard camp of the Florence Stockad using a trackhoe to excavate ever expanding holes around the well shafts with hand excavation of the fill, but only had to go a litte over 20 feet deep to get to the bottoms of the well. Even then we had very large holes when we were finished.

Pat


-----Original Message-----
>From: Richard Wright <[log in to unmask]>
>Sent: May 13, 2013 8:41 PM
>To: [log in to unmask]
>Subject: Re: The archaeological excavation of wells
>
>Pat
>
>Couldn't agree more about the dangers (though some have incorrectly 
>assumed I might be a cowboy).
>
>Are there accessible illustrations of the work in progress, using cement 
>liners? That is the sort of archaeological work that I originally asked 
>about.
>
>This is a useful document on how excavation of trenches and shafts 
>should be done in Australia.
>
>http://www.safeworkaustralia.gov.au/sites/swa/about/publications/pages/excavation-work
>
>Richard
>
>On 14/05/2013 05:23, Pat Garrow wrote:
>> Tim is absolutely right. Well excavation is dangerous and should only be attempted with all proper safety equipment and precautions. Garrow & Associates excavated a deep well on the Oxon Hill Manor site using concrete well links as a liner. Well links can be made in a size to fit the interior diameter of the well and generally come in 3 foot sections. The sections interlock and provide a secure work area. You have to be very careful about keeping the well links level and comply with OSHA's confined space regulations. Perhaps the best thing to do when considering a well excavation is to determine if the risk can, at any level, match the rewards that can be gained from excavation. I try to avoid doing wells at this point, and feel that it is putting staff unnecessarily at risk.
>>
>>
>> -----Original Message-----
>>> From: scarlett <[log in to unmask]>
>>> Sent: May 10, 2013 2:41 AM
>>> To: [log in to unmask]
>>> Subject: Re: The archaeological excavation of wells
>>>
>>> Richard,
>>>
>>> I don't think you will find an archaeological manual that deals with this.  In my opinion, you should not look for one.  This is a very serious issue on which you should consult with a professional.  For example, you have left off of your list of risks hazardous like CO2/gas buildup and water accumulation.  Not only is special knowledge required to design and construct the reinforcing, but employees entering such a confined space are required to have special training. Also keep in mind that there are many, many factors that figure into designing a safety strategy, including sediment type, moisture, groundwater level, vibration from nearby roads, the weight of nearby structures.  Many of these issues are not self-evident to someone that lacks training. As conditions often vary, there isn't one standard plan.
>>>
>>> A man just died today in our region, trying to fix a well:
>>> http://www.chicagotribune.com/news/local/ct-met-dry-ice-death-20130510,0,6601881.story
>>> A non-archaeological example where they were using the dry ice to improve the porosity of the well (I think). While this seems a silly example, I have seen groundwater contamination strong enough it would foul the atmosphere and cause a person to loose consciousness in a confined excavation exactly like this case, which would require the rest of the crew to conduct an extraction.  That guy's buddy wasn't prepared to be able to extract him and he died.
>>>
>>> Some technical literature is published in the United States through OSHA (as you probably know, Australia, Canada, and the EU have their government safety organizations with online information), but you should really consult with a construction engineer who knows the laws and best practices, or perhaps a first responder that has special training.  These sites list the government publications:
>>> http://www.osha.gov/SLTC/trenchingexcavation/
>>> http://www.osha.gov/doc/outreachtraining/htmlfiles/excavate.html
>>> http://www.osha.gov/doc/outreachtraining/htmlfiles/cspace.html
>>>
>>> Cheers,
>>> Tim Scarlett
>>>
>>>
>>> On May 9, 2013, at 9:40 PM, Richard Wright wrote:
>>>
>>>> The dangers for archaeologists excavating old wells in superficial deposits are self-evident.
>>>>
>>>> Two fundamental methods of preventing the dangers of collapse are (1) shoring, or (2) creating a safety zone by progressively excavating away the soil around the well as the excavation of the contents proceeds.
>>>>
>>>> Can anyone point me to publications that discuss these dangers and how they can be prevented - preferably with illustrations.
>>>>
>>>> Richard Wright