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Hurn Court FarmComes on StreamNew Milton Sand and Ballast open new greenfield sand and gravel site adjacentto Bournemouth Airport

Since their foundation some 70 yearsago, New Milton Sand and Ballast(NMSB) – a wholly owned subsidiary ofH.H. & D.E. Drew Ltd – have

established themselves as a relatively small buthighly successful regional business providinghigh-quality aggregate, concrete and wastesolutions to meet the demands of a particularniche market – namely the smaller builders,local tradesmen and householders in andaround the southern counties of Hampshireand Dorset.

Based in the Hampshire town from whichthe business takes its trading name, NMSB areowned by joint managing director MichaelBadcock (12%), the Drew Family Trust (39%)

and Hanson Aggregates (49%), with thecompany’s board of directors comprising MrBadcock and recently appointed joint managingdirector Trevor Poole, together with threemembers of the family trust and onerepresentative from Hanson.This managementstructure allows the company to operate as awholly independent organization but with thesecurity of a ‘big company’ umbrella, althoughHanson have no controlling interest in theday-to-day management and operation of thebusiness.

Today the company has a turnover ofaround £14 million, employs over 90 staff andhas various operations extending fromWareham in the west to Lymington in the ä

Aerial view of New Milton Sand and Ballast’s new greenfield sand and gravel operation at Hurn Court Farm

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east.These include: four sand and gravelextraction sites, two of which are equippedwith washing plants; one bagging plant; twoready-mixed concrete plants and a mini-mixbusiness; a sand quarry joint venture inDorset; one waste recycling site; and threewaste-transfer/collect aggregates depots withassociated skip and muckaway services. NMSBare also looking to expand their washedsecondary aggregates and small-loadmerchanting activities, and have recentlyacquired Steve Perrins Supplies Ltd, theRingwood-based building supplies business.

The latest NMSB extraction and processingoperation to come on stream is a £4.5 million development on a 185-acregreenfield site at Hurn Court Farm, adjacentto Bournemouth Airport. Owing to the heightof the local water table and the potential forstanding water, the current planning consentallows for the extraction of 1.8 million tonnesfrom total proven reserves of around 2.2 million tonnes.This means that some 1.5m of the 4m thick sand and gravel depositwill have to be left in the ground, as the site’sclose proximity to the airport prohibits thepresence of large open water bodies, balancingponds, silt lagoons etc, which could attractflocks of migrating birds. NMSB plan to workthe site at a rate of 140,000 tonnes per annumover a 12-year period, with a rollingrestoration scheme being used to replacecarefully preserved topsoils and subsoils toreturn the land back to agriculture, albeit at aslightly lower elevation than before.

The first phase of development at the siteinvolved the relocation of an existing road tocreate suitable access to the site, the re-routing of a high-pressure gas main and roadjunction works to an airport entrance adjacentto the site.This was followed by the

installation of a 150 tonnes/h sand and gravelwashing/processing plant, supplied and installedby Co.Tyrone-based CDE Ltd andcommissioned in May 2007. Once again,proximity to the airport imposed certainrestrictions, with a maximum permitted heightof 10m for the processing plant structure anda 7m height limit for product stockpiles.Theplant itself produces two grades of washedsand and features two separate coarseproduct lines, one producing a range ofwashed and graded natural ‘shingle’ products,which are particularly suitable for decorativepurposes, and the second producing washedand crushed 20mm and 10mm aggregatessuitable for use in concrete production.

Sand and gravel plantThe new plant encompasses CDE’s full rangeof equipment, including a feed hopper, anumber of models from the company’sProGrade screen range, a RotoMax log-washer, an EvoWash multi-sands plant, anAquaCycle high-rate thickener, together withan Ore Sizer VSI crusher and Klein belt press,as well as several transfer conveyors of variousspecifications.

A raised access ramp allows mobile plant tofeed the raw material (comprisingapproximately 48% sand and 52% gravel) intothe processing plant’s 35-tonne capacity feedhopper, which discharges on to a 25m inclinedtransfer conveyor.This, in turn, feeds thematerial on to the first of the CDE ProGradescreens, a 5.0m x 1.8m double-deck rinsingunit that offers the maximum open area toensure the highest possible tonnage over thescreen, while also increasing the unit’sdewatering capability.

Approximately 10 tonnes/h of +60mmoversize is rejected by the top deck of the

View showing part of the 150 tonnes/h CDEwashing/processing plant

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screen and discharged to an adjacent oversizebay, while the sand from the feed material(approximately 60 tonnes/h) is washedthrough the bottom deck of the rinsing screenand piped to the EvoWash multi-sands plant.Meanwhile, the –60mm +5mm material(approximately 80 tonnes/h) is fed into an 82/7RotoMax log-washer equipped with long-lifechrome molybdenum blades for reduced wear.The entire plant uses 35m3 of water per day,most of which is recycled, with any top-uprequired being supplied by an on-siteborehole.

Scrubbed material from the log-washer isdischarged from the front of the unit on tothe second ProGrade screen, this time a 3.0mx 1.5m double-deck rinsing unit, while thewaste water from the rear of the log-washeris piped to the EvoWash multi-sands plant.

From this point on the plant splits into twoseparate lines, one for natural (uncrushed)shingle suitable for decorative purposes, andthe other for crushed aggregate suitable foruse in concrete.The –60mm +24mm oversizedischarged from the top deck of the secondrinsing screen (approximately 25 tonnes/h) isconveyed to the crushing station, while the–24mm +6mm (approximately 50 tonnes/h)passes over the bottom deck and is conveyedto the natural screening station.Any remainingsand is washed through the bottom deck andfed to a ground sump. From here a verticalWarman pump is used to pump the sand andwater slurry to the EvoWash plant.

The natural screening station, which is fedby a 25m inclined transfer conveyor, consistsof a 3.0m x 1.2m double-deck horizontal HRscreen, a 6m transfer conveyor and another2.4m x 1.2m single-deck horizontal ProGradescreen, all fixed to a metal structure mountedon concrete walls that form a series ofstockpile bays.The 6mm product passes

through the bottom deck of the first screenand drops into a bay directly below, while the–10mm +6mm product passes over thebottom deck and is discharged into theadjacent bay.The +10mm material that passesover the top deck is fed on to the shorttransfer conveyor and discharged on to thesingle-deck horizontal screen.This separatesthe 14mm and 20mm products, which aredeposited into their respective bays.

Meanwhile, the –60mm +24mm oversizefrom the second ProGrade screen is conveyedto the crusher station, which comprises a 6-tonne capacity surge bin mounted above anOre Sizer OM50 vertical-shaft impact crusher.An ultrasonic level probe located within thesurge bin controls a vibrating feeder to ensurea constant feed to the crusher, which has athroughput capacity of 40–50 tonnes/h.Thecrushed product from the OM50 is conveyedto the crushed product screening station ä

Final screen arrangement andproduct bays

The Ore Sizer OM50 VSIcrusher

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via a 24m inclined transfer conveyor.This transfer conveyor feeds on to a 4.0m x

1.5m triple-deck ProGrade rinsing screen,whereupon any oversize passes over the topdeck and on to a transfer conveyor fordischarge into an end bay, while 20mm and10mm crushed products pass over the middleand bottom decks, respectively, and aredischarged into separate bays below.The–5mm material and wash water is piped into asump; from here a Warman 6/4 pump transfersthe slurry to the EvoWash plant.

The EvoWash multi-sands plant, whichallows NMSB to define the required cutpoints, processes approximately 70 tonnes/h(60 tonnes/h from the first screen and 10 tonnes/h from the other screens) of sandcontaining fragments of wood and lignite.TheEvoWash process utilizes a series of cyclones,upward-flow classification tanks, sieve bendsand dewatering screens to maximize thequantity of sand produced, while eliminatingthe contaminants and reducing the loss offines.The end result is two clean sandproducts – a washed concrete sand and awashed building (plastering) sand, both with amoisture content of around 12% – togetherwith a lignite-contaminated ‘waste’ sand.

Meanwhile, owing to the prohibition onsettlement ponds at Hurn Court Farm, awater-treatment plant and belt press are usedto deal with the waste water and fines.The–63 micron slurry discharged from theEvoWash multi-sands plant (approximately400m3/h) is piped into an 8m diameterAquaCycle high-rate thickener tank, into whichboth cationic and anionic polyelectrolytesolutions are dosed to help settle the solids,while the clean water overflow is recycledback to the site’s main storage tank for

recirculation and reuse.The sludge produced by the thickener tank

is pumped into a 60m3 buffer tank locatedbeneath a 2.5m wide Klein belt press, which ishoused in a fully clad building, together withthe flocculant mixing and dosing equipment.The press is fed using a 6in seepex pump, withthe sludge being dosed with both anionic andcationic polyelectrolytes, to aid the dewateringprocess in the belt press, before passingthrough two in-line mixers in the press feedpipe.The press discharges up to 12 tonnes/hof pressed filter cake, while the filtratesolution is recycled back to the washing plantvia the AquaCycle high-rate thickener.After aperiod of natural drying, the waste filter cakeis later returned to the land as part of thesite’s restoration process.

Concrete plantHurn Court Farm is also the location of NewMilton Sand and Ballast’s second and newestready-mixed concrete plant. Supplied andinstalled by Co.Tyrone-based McCroryEngineering and commissioned in June 2007,the low-level plant features: two separate setsof in-line-feed bins, each with its own weighbelt; a covered feed conveyor; a gantry-mounted 4m3 capacity Pemat planetary mixer;two 50-tonne capacity cement silos; and a30,000-litre water tank.

The plant has a nominal capacity of 60m3/h,but the twin feed lines cater for multi-batching, with one line weighing the next batchwhile the previous batch is being discharged,resulting in an actual capacity of around80m3/h. Plant monitoring and control is via aPracticon control system, which works inconjunction with Weighsoft software toprovide fully automatic operation with varying

View of the CDE EvoWashsand plant and stockpilingconveyors

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degrees of operator intervention as and whenrequired.The plant is equipped with twodischarge doors, one for transit mixers andthe other suitable for smaller flat-bed vehicles.The plant’s steel support structure has alsobeen designed so as to allow larger tipperwagons to back into position under bothdischarge doors for rapid loading of floorscreeds.

NMSB have also invested in three DAFtrucks featuring fully demountable andinterchangeable 4m3 Hymix mixer units and10.75-tonne capacity Wilcox Wilcolite tipperbodies. Offering greater delivery flexibility andimproved truck utilization, these have alreadyproved so successful and versatile that thecompany is planning to buy another threesimilarly equipped vehicles.The company alsoowns and operates its own 37m3 capacity bulkcement delivery tanker, which makes aparticularly striking sight in its bright orangeand white livery.

Main marketsThe south coast towns of Poole andBournemouth, which lie just to the south ofHurn Court Farm, provide the largest outletsfor the site’s products. New Milton Sand andBallast deliberately choose not to compete formajor contracts in the region, insteadpreferring to focus attention on the sale oftheir ISO 9001-accredited bulk sands andgravels, decorative bagged aggregates, ready-mixed concrete and floor screeds direct tosmaller end-users, trade customers, localbuilders and householders.As a result, much ofsite’s output is used in smaller building andrenovation works, house extensions, garages,garden walls etc.This marketing strategyworks particularly well for the company,helping to minimize the seasonal fluctuationsin demand experienced by some of theirlarger competitors.

Despite their inclination to shy away fromthe region’s bigger jobs, one major contract onHurn Court Farm’s doorstep that NMSB arehoping to win a share of is the redevelopmentof Bournemouth Airport. Last year the airportwas given the go-ahead for a £32 millionexpansion project involving the constructionof a new arrivals hall and departure lounge,additional aircraft parking stands and extra carparking facilities to accommodate a predictedtrebling of passenger numbers within the next10 years.The redevelopment work isscheduled to take place over the next four tofive years, and with the airport located, quiteliterally, just across the road from Hurn CourtFarm, this opportunity is regarded by thecompany as one large job that really would betoo good to miss.

AcknowledgementThe editor wishes to thank New Milton Sandand Ballast for permission to visit their HurnCourt Farm site and, in particular,TrevorPoole, joint managing director, for his help inpreparing this article.

View of the ready-mixedconcrete plant supplied byMcCrory Engineering

NMSB’s 37m3 bulk cementdelivery tanker, lookingresplendent in its orange andwhite livery