In our opinion this table simplifies the often over-complicated subject of accuracy and scale and should be used by clients and survey professionals alike.
See below:
Ogilvie Geomatics
Monday, 29 September 2014
Measured Surveys - 3rd Edition: Survey Detail Accuracy Banding Table
The latest edition of Measured surveys of land, buildings and utilities - RICS guidance note contains a useful table outlining accuracies bands, requirements and features depending on the Survey type/use and legacy output scale.
In our opinion this table simplifies the often over-complicated subject of accuracy and scale and should be used by clients and survey professionals alike.
See below:
In our opinion this table simplifies the often over-complicated subject of accuracy and scale and should be used by clients and survey professionals alike.
See below:
Wednesday, 9 July 2014
Ogilvie Geomatics attend launch of PAS 128 - Specification for underground utility detection
Mark McGarragh and Gordon Crichton attended the recent launch of the PAS 128 specification for underground utility detection, verification and location at the Institution of Civil Engineers (ICE).
To view the seminar online visit:
www.ice.org.uk/Events-conferences/Recorded-lectures/Lectures
We were particularly interested in Andy Rhoades presentation with regards to Heathrow airport. They had a near miss whereby a lightning rod was literally inches from piercing a main fuel line due to a lack of briefing, and understanding of the the utility plans.
The result was potentially catastrophic! Such pollution from an incident would cost £100k to £1m's to clean up and could take a least 2 months - shutting down Heathrow airport.
Further info on PAS 128:
As the demand on the nation’s infrastructure continues to grow due to new developments, the need to replace and/or maintain existing utilities increases. It is therefore essential that accurate information about where underground utilities are actually located is available.
Historically this has been hard to achieve as the detection, verification and location of utility assets have been subject to interpretation and inaccuracies. This has led to the safety of workers and the public being put at risk, unnecessary work that has often needed to be aborted, damage to third party assets and inefficient design solutions.
PAS 128 aims to provide a clear and unambiguous provision for those engaged in the detection, verification and location of active, abandoned, redundant or unknown utilities. It is applicable to surveyors, geophysicists or subsurface utility engineers as well as engineers, constructors, project managers and utility owners who are responsible for recording information about underground utilities.
To download the PAS 128 specification visit:
shop.bsigroup.com/en/ProductDetail/?pid=000000000030267400
Monday, 14 April 2014
Punctured rail tunnel renews calls for better utility/infrastructure information
Source: Geomatics World
It was only train driver vigilance and a measure of good luck that prevented a serious rail accident on Network Rail’s Northern City Line tunnel between Old Street and Essex Road stations in London on March 8th 2013. A driver reported seeing water pouring through the roof of the tunnel as he passed through. Then a second driver, who was sent with an out-ofservice train to investigate, found a pile boring bit and debris on the tracks. The incident was caused by piling from a building site 13m above the tunnel puncturing the tunnel lining.
The tunnel is owned by Network Rail, but because the developer was not aware of its presence, a search had not been requested. The local authority also failed to pick up the presence of the underground railway during the planning application process for the same reasons. Concerning mapping, some, but not all railway tunnels are shown on OS mapping. The report does not make a recommendation concerning this apparent inconsistency but instead recommends that railway infrastructure owners should publish information concerning railways that are not shown on OS maps.
You can read more at
It was only train driver vigilance and a measure of good luck that prevented a serious rail accident on Network Rail’s Northern City Line tunnel between Old Street and Essex Road stations in London on March 8th 2013. A driver reported seeing water pouring through the roof of the tunnel as he passed through. Then a second driver, who was sent with an out-ofservice train to investigate, found a pile boring bit and debris on the tracks. The incident was caused by piling from a building site 13m above the tunnel puncturing the tunnel lining.
The Rail Accident Investigation Branch (RAIB) published its report
on 14th February 2014 – eleven months after the incident. The investigation found that no one knew about the tunnel beneath the site. The tunnel route is not shown on OSMasterMap or historical OS mapping. The presence of a tunnel is hinted-at, somewhat cryptically in the registered title for the site, which states: “So much of the sub-soil as was vested in the Great Northern and City Railway is excluded from the registration”.
The tunnel is owned by Network Rail, but because the developer was not aware of its presence, a search had not been requested. The local authority also failed to pick up the presence of the underground railway during the planning application process for the same reasons. Concerning mapping, some, but not all railway tunnels are shown on OS mapping. The report does not make a recommendation concerning this apparent inconsistency but instead recommends that railway infrastructure owners should publish information concerning railways that are not shown on OS maps.
You can read more at
http://www.raib.gov.uk/publications/investigation_reports/reports_2014/report032014.cfm
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