Amble and District
     Local History


The Broomhill / Amble Undersea Project
A Viewpoint by
Dr. Eric Wade

Webmaster's note: this paper was published in the early 1980s, when the potential of a new colliery at Amble was being evaluated.
  1 Background
  2 Geological Structure
  3 Coal Seams
  4 A Historical Perspective
  5 Future Development
  6 Illustrations
1. Background
     The Broomhill/Amble area lies at the northern extremity of the Northumberland and Durham Coalfield (Fig.1) . The area has a long history of coal mining dating from the period 1825-1850 (Fig.2). The Broomhill mining field developed separately from the rest of the coalfield. One consequence of this separate development was the distinctive nomenclature of the coal seams. In recent years the National Coal Board have attempted to correlate the "Broomhill/Hauxley" seams with the rest of the coalfield (Fig.3).

    The long history of coal mining in the area is not totally insignificant to the future development of the area as a source of important undersea coal mining expansion. The main exploiters of the mining field have been the Radcliffe Coal Co. Ltd., Broomhill Coal Co. Ltd., Broomhill Collieries Ltd., and the National Coal Board. At the present time the on-shore area is an important source of Opencast coal mining production and will continue as an important source of this type of production well into the 1990's.

    The main collieries in the mining field were Radcliffe Colliery (closed 1895) Newburgh or New Radcliffe Colliery (closed 1926) Broomhill Colliery (closed 1961) and Hauxley Colliery (closed 1966). Surface traces of all four collieries have been obliterated by opencast mining. The only working collieries in the vicinity of the undersea mining project area are Shilbottle/Whittle Colliery complex 7 miles to the North West and Ellington-Lynemouth Colliery complex 7 miles due South (Fig.4).
2. Geological Structure
    The carboniferous geology of northern England with some reference to the Broomhill-Amble area has been described by a number of workers. The most important sources have been HICKLING ("Prospects of undersea coalfield extension in the North-East" Trans. Instn. Min. Engrs. 1949-50 109.659) CLARKE et al ("A Marine Geophysical survey of the Undersea Coalfields of Northumberland, Durham & Cumberland" Min. Engr. 1961-62). Recent off-shore drilling and seismic work by the N.C.B. has yielded much new information about the mining field.

    Geological structure plays an important role in delineating the off-shore possibilities of mining. The Major fault pattern is of a general East West trend (Fig.5). The assumed southern boundary of the field is the Causey Park Whin Dyke. The Causey Park Whin Dyke is part of a dyke echelon associated with the Great Whin Sill (Fig.6). The Causey Park Dyke forms a conspicuous feature in the records of a "sparker" survey of the undersea extension of the Broomhill/Hauxley area described by CLARKE et al (Fig.7). In 1973 metamorphose sandstone and "coked" coal was recovered from bore hole No.9 drilled from the Wimpey "Sealab" part of a N.C.B. seismic survey, some 4 miles offshore in line with the dyke (Fig.8). The dyke is also a fault and it has a downthrow of 200 ft to the North and every indication suggests that it will maintain this amplitude in the offshore area. Broomhill Colliery proved the dyke/fault line in numerous workings. In one district, Linkhouse Queen (H1) seam South Winning, the colliery attempted to breach the dyke, but difficulties arose with "running sand" in 1953.

    The mining field is also divided by another dyke, the Acklington Dyke. This dyke is very persistent, and its line can be traced with great accuracy across northern England and it is expected that it will persist in the offshore area (Fig.9). Complications arise with this dyke in the vicinity of Newburgh. The dyke although it has no fault features, i.e. no throw throughout the majority of its length, at Newburgh it merges with the Bondicarr Fault. The Bondicarr fault has a maximum downthrow of 450 feet to the South. Both the Bondicarr fault and the Acklington dyke are present off-shore. The Bondicarr fault's amplitude diminishes to 200 ft according to CLARK et al "sparker" Survey. The exact alignment of the Acklington dyke offshore is unclear although it has been identified on the Bondicarr rocks near Newburgh. Hauxley Colliery workings from the East Drift area, in the Duke  (K2) seam and the Princess  (K1) seam, obtained cinder coal attributed to the dyke.

    The next major structural feature is the important Hauxley Fault. Hitherto the fault has been described as the northern limit of the Northumberland coalfield (Fig.1). Undoubtedly this fault is the landward limit of the coalfield, however, borings by the NCB suggest that workable coal seams do exist North of the fault. North of the fault, the Hauxley Brockwell (T) seam was worked by Hauxley Colliery between 1957-1966 both off and on-shore. The fault has a maximum downthrow of 900 ft to the South. In the vicinity of the fault on the downthrow side, the strata shows steep dips (Fig.10) . A second feature of the fault is the development of subsidiary folding along the plane of the fault. This was displayed, in the Broomhill Colliery workings, in the Moorhouse District, west of Radcliffe Colliery.

    Since workings to the North of the Hauxley fault have been limited to the Hauxley Brockwell (T) seam, knowledge of faulting is meagre especially in the offshore area. A fault of a downthrow to the North of 60 ft was encountered in the Brockwell (T) seam drift and two further faults were encountered in the Brockwell (T) seam workings although the amplitude was less than 15 feet. In the rock exposures surrounding Coquet Island two faults of unknown amplitude are displayed (Fig.10). A fault with a downthrow to the North has a persistent landward exposure adjacent to the middle of Alnmouth Bay. This fault is expected to persist into the offshore area with an unknown amplitude (Fig.1).

    A structural feature that will have an important effect on any mining development is the "Broomhill Dome". Domes are a feature of the Northumberland and Durham coalfield and are associated with major faulting. Well known domes exist off-shore at Newbiggin, Whitley Bay, Horton and Vane Tempest (Fig.8). The "Broomhill Dome" although smaller than the other domes, nevertheless it is still an important control feature and it does limit mining possibilities. The northern flank of the dome was proved in the Newburgh Colliery Queen (H1) seam and the Princess (K1) workings during the period 1896-1915. Broomhill Colliery attempted to further delineate the dome. In 1901-2 a Bord and Pillar winning was driven in Linkhouse Main (K2) seam parallel with the Causey Park Whin Dyke in an easterly direction under the sea. Insufficient cover existed between the seam driving horizon and the sea bed, the winning was continued for a further 50 yards in the bottom section of the Main (K2) seam and then abandoned. In 1953 a further attempt was made in the Chevington Main (K2) seam district. A short long wall winning face in the bottom section of the Main (K2) seam known as the "Crab Flat !" attempted to prove the amplitude of the dome, in the central area. The results were disappointing, the seam was gently rising, proving that the Main Seam (K2) at that point was still on the western flank of the dome and the peak of the dome in the Main (K2) seam would lie further offshore than envisaged. The 1962 "Sparker" survey showed that the eastern flank of the dome, the inclination of the seams were "gentler" than envisaged, consequently this means that the coal seams lie nearer the seabed than originally postulated. The "Sparker" survey also indicated two E-W faults probably a continuation of the Chevington No.1 and No.2 faults on the eastern flank of the dome.
3. Coal Seams
    The coal seams of the Broomhill field display characteristics which if continued could affect mining development in the off-shore area. As mentioned previously the Broomhill field developed separately, with a separate seam nomenclature unique to that part of the coalfield. Only after all underground mining had ceased, were there any real attempts to correlate all the seams with the rest of the coalfield. In the vicinity of Broomhill many coal seams outcrop (Fig. 11). In the southern section of the field, the coal seams deteriorate and split in an easterly direction, banding increases to enable the separate leaves of the coal seam to be worked as distinct seams. The top section of the Top or Princess (K1) seam was worked in the Linkhouse district adjacent to the Causey Park Whin Dyke. The Main (K2) seam was worked as two distinct sections in the Chevington district. It is suggested that the Duke (K2) seam of Hauxley is in fact the bottom section of the Main (K2) seam.. The Bottom or Yard (L) seam has a reduced thickness in the South-East area of the landward field as compared to the rest of the field.

    The coal seams in the northern part of the landward field maintain their section throughout the field particularly the Radcliffe (F) seam and the Albert (G) seam. The Queen (H1) seam and the Little Wonder (H2) are remarkable for their consistency throughout the field. North of the Hauxley Fault, the Hauxley Brockwell (T) seam, displays it's maximum thickness undersea. In Newburgh Colliery workings the Queen (H1) seam and the Princess (K1) seam after an area of relatively thin sections, both seams displayed thicker sections before the workings were abandoned in 1916.

    The Broomhill/Hauxley coal seams are generally fairly low in carbon content. The upper seams such as the Radcliffe (F) seam and the Albert (G) seam have a carbon content between 79.0 to 82.5%. They are weakly caking and the calorific value ranges between 14,250 to 14,750 B.Th.U. per lb. The lower seams are medium caking, typical Northumberland coal with a carbon content ranging from 82.5 to 84.59% and a calorific value between 14,600 to 15,100 B.Th.U. per lb. There is some alteration of the chemical composition of the coal seams in the vicinity of the two whin dykes that traverse the field especially the Causey Park Whin Dyke (Fig.12).
4. A Historical Perspective
   Ironically it was in the Broomhill/Hauxley area where undersea coal mining was pioneered. Newburgh Colliery or "New Radcliffe" Colliery was opened in 1895 by the Radcliffe Coal Co. Ltd., to exploit the undersea coal beneath the Newburgh No.1 Crown Royalty. In 1896, Broomhill Coal Co. Ltd., acquired the Radcliffe Coal Co. Ltd., and further developed Newburgh Colliery. In 1898 workings had progressed in the Queen (H1) seam on the northern flank of the Broomhill Dome. Knowledge of the geological structure of the coal seams was meagre. Exposures on the rocks surrounding Newburgh were traced and a borehole was drilled on the Bondicarr rocks. The borehole at the extreme point of the low water mark prove the following:
Radcliffe (F) seam at 24 Fms
Albert (G) seam at 42 Fms
Queen (H1) seam at 59 Fms
Princess (K1) seam at 73 Fms
      The Hauxley fault first encountered in the Radcliffe Colliery workings and Acklington Whin Dyke and the Bondicarr fault all can be traced as exposures on the rocks on the sea shore.
     The workings in the Queen (H1) seam were initially Bord and Pillar with a 40% extraction; the pillars were later removed. A drift was driven to the Princess (K1) seam and it was worked similar to the Queen (H1) seam although the Queen (H1) seam workings were always in advance of the Princess (K1) seam. It was at Newburgh Colliery that the first guidelines for undersea coal mine workings were developed. The Chairman of the Broomhill Coal Co. Ltd., and it's successor company in 1900 was Professor Hermann Merivale, the first professor of mining at the University of Durham an eminent practical mining engineer. He arbitrarily proposed that the limit to workings between the coal seam and the seabed should be 40 fathoms if total extraction was required. Partial extraction of 40% could be practiced between 40 fathoms and 30 fathoms. The upper mining limit being 30 fathoms. It is this guideline that forms the basis of all undersea coal mining extraction practice in the world today.

    In 1900, the Broomhill Coal Co. Ltd., was reorganised to form the Broomhill. Collieries Ltd. As a result of reorganisation plans were made for the future development of the company to work the undersea royalties, namely the Newburgh No.1 Crown Royalty, South of the Acklington Whin Dyke/Bondicarr
Fault. The adjacent Broomhill Crown Royalty that extended South of the Causey Park Whin Dyke. The company also intended to work the Newburgh No.2 Crown Royalty North of the Hauxley Fault. In 1901 a report, Bainbridge and Morison Broomhill Collieries Co. Ltd., 1901 REPORT, outlining the future plans of the company was published.
    It was proposed to drive a level cross-measure drift at a depth of 80 fathoms from Newburgh Colliery north towards the Hauxley Fault. As the coal seams were intersected, the landward coal would be worked, and the coals drawn at Newburgh Colliery. A new colliery was proposed at Hauxley at the intersection of the drift with the Hauxley Fault. The new colliery would be a mine to work exclusively the under sea coal between the Hauxley Fault and the Dyke, adhering to the 40 fathoms guideline (Fig.13) . This coal would be exploited by another cross-measure drift intersecting the steeply inclined coal seams in a South-East direction. It was tentatively proposed that a further winning should be developed North of the Hauxley Fault in the direction of Coquet Island.
A new colliery was proposed at Linkhouse. This colliery was to exploit the undersea coal of the Broomhill Crown Royalty working both North and South of the Causey Park Whin Dyke. A surface railway was proposed to be developed from the new colliery to Warkworth Harbour at Amble with a possible link to the proposed sinking at Ellington by Ashington Coal Co. Ltd., (Fig.13).

    The Linkhouse Colliery was never developed. The proposal for Hauxley Colliery was eventually enacted although the pace of development was retarded due to the First World War 1914-18 and the lack of investment funds. In 1923 the sinking of Hauxley Colliery Shaft was commenced, to sink onto the preformed shaft bottom of the junction of the Newburgh/Hauxley Drift and the Hauxley Fault. Hauxley Colliery was never developed to its full potential as originally envisaged by the BAINBRIDGE and MORISON REPORT 1901.

     In 1915, due to lack of investment funds and the shortage of manpower due to the First World War, Professor Hermann Merivale discussed the future development of Broomhill Collieries Ltd. (THE MANOR OF AMBLE, ITS MINERAL RESOURCES AND THEIR DEVELOPMENT). Newburgh Colliery was experiencing financial difficulties due to the deterioration of the Undersea Queen (H1) seam workings although at the time of publication of the report April 1915, improved seam sections of the  Queen (H1) seam were being experienced. It was hoped that the area of relatively thin coal less than 3 feet had been overcome, and sections of more than 3 feet could be expected.

    In 1916, it was decided to abandon the undersea workings of Newburgh Colliery and concentrate on coal work from the cross-measure drift where the coal seams were thicker. Newburgh Colliery was eventually closed in 1928 and it was replaced as a producing unit by Hauxley Colliery.
Hauxley Colliery remained a small colliery with manpower less than 400 for the remainder of the life of the Broomhill Collieries Ltd., until the closure of Broomhill Colliery by the N.C.B. in 1961, when the colliery was reorganised with double the manpower. Post 1947, development included a South-East Drift, working the undersea coal. of the Queen (H1) and Princess (K1) and Duke (K2) seam Hand-filled Longwall conveyors were worked to the rise terminating at the cinder coal of the Acklington Whin Dyke. In 1957, the Hauxley Brockwell (T) Drift was opened. In 1960 all workings were concentrated North of the Hauxley Fault in the Hauxley Brockwell (T) Seam until closure in 1966.
5. Future Development
     Any future development of the undersea coal in the Broomhill - Amble area must take into account: (1) the historical exploitation of the coal seams, (2) geological: structure, (3) recent Opencast coal workings, (4) Surface topography. All four factors act as a constraint on any future development.
The workings of Newburgh, Broomhill and Hauxley Collieries are well known and documented. Through mining activity and the N.C.B. off-shore exploration programme, the delineation of the geological structure is well known.

    The potential mining field split into three distinct sections (1) the area North of the Hauxley Fault (2) the area between the Hauxley Fault and the Acklington Whin Dyke and (3) the area between the Acklington Whin Dyke and (3) the area between the Acklington Whin Dyke Bondicarr Fault and the Causey Park Whin Dyke (Figs. 7, 11 & 13) .

     In the northerly section (1), the reserves lie in the lower seams i.e. the Three Quarter (R) seam 48"/60" - 30 million tonnes, the Victoria (Hauxley Brockwell (T) ) seam 36"/84" - 75 million tonnes and the Marshall Green (U) seam 36"/48 - 10 million tonnes. This area is relatively free of major faulting and the inclinations of the seams are gentle, maximum gradient in the S.E. direction of 1 in 14 approximately. This section would present few mining problems, although all three seams outcrop in the sea-bed, giving rise to possible wet conditions. The Hauxley Brockwell (T) seam was notorious for adverse wet conditions.

     In the middle section (2), the coal seams are steeply inclined with the major dip northwards in the direction of the Hauxly fault. There is the possibility of further subsidiary folding along the plane of the fault. Some seams have already been worked by Hauxley Colliery namely the Queen (H1), the Princess (K1) and the Duke (K2) seams. Although reserves still exist in all three seams in addition to reserves in Radcliffe (F) and Albert (G) seams, barrier pillars would have to be left to isolate the old Hauxley workings.

    In the southern sections (3), the constraining influence is the "Broomhill Dome" (Fig.8) and the old Newburgh Colliery workings in the Queen (H1) and the Princess (K1) seams. Substantial coal reserves do exist in this section in the Radcliffe (High Main & Main) (F) seam 36"/60" - 15 million tonnes, the Queen (H1) and Little Wonder (H2) (Low Main) seams 36"/60" - 30 million tonnes and the Princess (K1) and Main (K2) (Brass Thill) seams 36"/120" - 90 million tonnes. In this area the seams are moderately inclined on the northern flank of the dome with the maximum gradient in the direction of the Bondicarr fault. On the eastern flank of the zone the seam inclinations are relatively gentle with a maximum gradient of 1  in 14. In the southern flank of the dome, the gradient changes direction to a gentle inclination in the S.E. direction.

    As previously described the nomenclature of the Broomhill seams are different from the rest of the coalfield and the N.C.B. give seam reserve information according to their own nomenclature and classification. Consequently the N.C.B. have indicated from their recent borehole exploration seam horizons with favourable sections.  There is the possibility that reserves do exist at other horizons that would make mining possible and obviously increase the recoverable reserves. The N.C.B. suggest that current North Area practice is to extract approximately 40% of "in situ" reserves, even using "total" extraction methods. Indications from their exploration programme that 250 million tonnes of "in situ" reserves exist with a recoverable reserve of 70 million tonnes. There is the distinct possibility that "in situ" reserves are fact higher than postulated.

    Recent Opencast workings are a very important factor in any future development. Coal Seams have been worked extensively from just North of the Hauxley Fault, in a southerly direction beyond the Causey Park Whin Dyke ultimately reaching the Grangewood fault. The coal seams have all been worked close to the sea links. This means that there is very little stable ground in the Broomhill/Amble area for any surface buildings, with access facilities to underground workings. The only stable ground lies, half-mile North of the Hauxley Fault extending along Alnmouth Bay to Boulmer.

    One of the biggest problems is the lack of rail facilities near the project area. Although North of the River Coquet the main British Rail, London to Edinburgh line lies very close to Alnmouth Bay (Fig.1). Also marshalling track exists for the Shilbottle and Whittle Collieries. Unfortunately between the River Coquet and Boulmer, the surface topography is such that it would be difficult and very costly to construct a rail access to any surface installation. Rail facilities did exist in the Amble area during the working lives of Broomhill and Hauxley Collieries (Fig.13). In 1970, the railway line between Amble and the main British Rail system was dismantled. The only reasonable access to the Amble area is by road. The Opencast Executive have constructed a subsidiary private road system for access to their sites in the area.

    It is very obvious that to open up the undersea area for mining would present a challenge to mine planners. One possibility would be to sink a new mine North of the Hauxley fault, south of the town of Amble: Previous mining operations would favour a drift access instead of a shaft. This would give access to the lower seams in the Broomhill/Hauxley succession, mining conditions would probably be best in this area, although seam sections would be relatively thin i.e. 36"/45". A main winning could be driven south, to open up areas south of the Hauxley fault. Major mining problems would be the negotiation of the Hauxley fault itself, the Acklington Whin Dyke and the Bondicarr fault. Mining conditions would be very different from those North of the fault, due to the inclination of the seams. However the seam sections would be thicker than those North of the Hauxley fault. A further advantage would be that the bulk of the reserves in the project area lie between the Acklington Whin Dyke and the Causey Park Dyke. The major problem with the Amble site scheme is the lack of rail facilities to transport the coal from the site.

    Another scheme would be to sink a new mine in the Linkhouse area ie the old Broomhill Collieries Co. Ltd., scheme (Fig.13). This mine would also have to be adrift mine. The main winnings would be constructed parallel with the Causey Park Dyke, with a further main winnings North, encountering the geological disturbances in the reverse order as described in the previous paragraph. Again the problem would be transporting the coals from the site. However this site would have an advantage, the existing Opencast private road system could be converted into a National Coal Board private rail system, to link with the coal screening plant at Widdrington junction.

    A third scheme would be to transport the coals underground to the Bewick Drift transport system of the Ellington-Lynemouth complex. A series of coastal drifts could be driven North of the Causey Park Dyke, for man-riding, ventilation and supplies. Ellington Colliery workings would have to be extended to drive through the Causey Park Dyke to give access to the coal in the undersea project (Fig.7). At the present time this would seem a tremendous underground transport system. However with improved communication and transport systems, this certainly could be a possibility for the 1990's.

    There is no doubt that considerable reserves of coal exist in the undersea area opposite Boulmer, Amble and Broomhill. It will require great vision and persistence by all concerned to get the project started. In hindsight it is a great pity that people responsible for the mining fortunes of the Broomhill/ Amble area in the early 1960's had not the vision of the pioneers of the Broomhill Collieries Co. Ltd. in 1901. They certainly conceived of the plan to mine the undersea coal, not only that their postulations concerning the geological structure of the area have proved to have been fairly accurate.
It now can be seen that the decision to close Hauxley Colliery on narrow accounting grounds without considering the wider possibilities of the area was a decision that now can be regretted regarding the future of coal mining in Northumberland.



Figure 3.

Standard N.C.B. names and index letter   Broomhill / Hauxley   North Northumberland
Ashington       ---------------- ------------------ ------------------   D/E Ashington
High Main E     ---------------- ------------------ ----------------- -[ E1 High Main
    E2 Diamond
Main F     --------------- Radcliffe ----------------- -[ F1 Middle Main
    F2 Bottom Main
Yard G     --------------- Albert ----------------- -[ G1 Bentinck
    G2 Yard
Maudlin H -[ H1 ---------------- Queen ----------------- -[ H1 Top Bensham
H2 ---------------- Little Wonder ---------------- H2 Bottom Bensham
Low Main J     --------------- Little Wonder (Opencast) -----------------     Five Quarter
Brass Thill K -[ K1 ---------------- Top or Princess ----------------     Low Main
K2 ---------------- Main or Duke    
Hutton L     --------------- Bottom or Yard -----------------     Plessey
Plessey M     ---------------- Cheeveley -----------------     Cheeveley or Bottom Plessey
Harvey N     --------------- Beaumont ------------------     Beaumont
Hodge O     --------------- ------------------ ------------------     Stobswood Tilley
Tilly P     --------------- Givens ---------------     Widdrington Yard
Top Busty Q -[ Q1 --------------- Widdrington 5 Quarter --------------- -[ Q1 Pegswood Harvey
Bottom Busty Q2 --------------- Widdrington Top Main --------------- Q2 Pegswood Top Busty
Three Quarter R     --------------- Widdrington Bottom Main ---------------     Pegswood Bottom Busty
Brockwell S     --------------- Bandy ---------------     Bandy
Victoria T     --------------- Hauxley Brockwell ---------------     Choppington Brockwell
Marshall Green U     --------------- Hauxley Victoria ---------------     Choppington Victoria


Amble Undersea Mining Area

Copyright ©  Dr. Eric Wade. Reproduced here with permission.