FAQ’s on Ground Anchors
Question: How did Ground Anchor accreditation commence and who is responsible for testing?
Answer: The National Association of Memorial Masons, with guidance from Professor John Knapton, whilst Head of Structural Mechanics at Newcastle University, devised a ground anchor accreditation test which was incorporated in British Standard 8415.
At the test location the device is tested with two NAMM Technical Committee members present and the results are recorded and witnessed by an independent structural engineer.
Once the reports prepared by the NAMM observers and the independent structural engineer have been reviewed, accreditation is then agreed by the NAMM Technical Committee.
Question: Do NAMM charge the Ground Anchor Manufacturers for accrediting their ground anchors?
Answer: Costs are involved in the accreditation of ground anchors, including the presence of the independent structural engineer and his reports to the NAMM Technical Committee. These costs and those of NAMM administration have always been arrived at on a non-profitmaking basis. It is in the interests of all memorial masons to have a wide choice of accredited devices competitively priced.
Question: Who pays the NAMM Technical Committee?
Answer: The NAMM Technical Committee consists of long time served, experienced, practical memorial mason volunteers. Only travelling expenses are reimbursed from NAMM membership funds.
Question: Are Ground Anchor Manufacturers allowed to sit on the NAMM Technical Committee?
Answer: As the NAMM Technical Committee has to cover a broad range of issues, input is welcome from any members with relevant technical knowledge. However, when any discussions involving those with a commercial interest take place, such as ground anchors, members cannot be involved and are asked to leave the room by the Chairman.
Question: Some press reports have stated that once fixed in place memorials are required to withstand a force of 150kg is this correct?
BS8415 requires that memorials with any component greater than 625mm above ground should be designed to withstand a force of 70kgs at its apex or 1.5 meters from ground level, whichever is the lower.
BS 8415 requires progressive failure type ground anchors to withstand a force of 100kg for 1 minute and, for a rigid system to withstand a force of 150kg for 1 minute.
Progressive failure type systems are defined as those which resist the 100kg force for 1 minute but, when subjected to a force over 100kg, gradually bend in the direction of the applied force in a controlled manner without sudden collapse.
Question: Recent press reports have stated that Ground Anchors are stability devices is this correct?
Answer: No, ground anchors are safety devices not stability and are designed to stop the memorial suddenly falling over.
Question: Are Ground Anchors designed to be vandal proof?
Answer: No, ground anchors, like most of the infrastructure around us, are not designed to be vandal proof, and a sustained attack on a memorial will most probably be successful. However, even in these abnormal conditions, a correctly installed anchor will still help to prevent sudden failure.
Question: Are all Ground Anchors designed for the same ground conditions?
Answer: No; the NAMM Code of Working Practice gives a number of alternative fixing options when installing a memorial on soft grounds, including traditional poured foundations. Generally, in softer ground conditions, a longer anchor or even two anchors are used. All NAMM accredited ground anchor manufacturers offer technical advice on their products.
Note: No injuries have been recorded since the introduction of the accredited ground anchor systems when correctly fitted to manufacturer’s specifications.