Ironstone Off-load Chutes and the SMJ Bridges

 Tony Marsh        19 December 2015 

One of the Ironstone Works images that was included in George Freeston's collection
was suspected of being attributed to an incorrect bridge (out of the total of four) which
cross the SMJ Railway cutting in Gayton parish. To "get it right" raised a number of
practical issues - it all developed into something of a challenge.

Introduction    Whilst the arrival of the SMJ railway* inconvenienced the earliest ironstone miners, it is clear that for a period that eventually extended to ~1950s the miners made good use of the railway to ship out the ore. In recent discussions with Barry Taylor, author of an emerging book on the SMJ railway, the question was raised regarding the location of the extremely distinctive ironstone off-loading installation depicted in the website photograph 18-09 and also shown here in the inset. It shows that the stages involved in the off-loading were to (a) position horse and cartload of stone in the box at road level (horse to the right), (b) open a hatch and the side of the cart to let sufficient load down into a trolley-wagon running on a level set of rails, (c) roll the trolley to its limit of travel and open its end (and maybe tilt it) to (d) facilitate it being emptied into a chute over a rail wagon waiting at a siding to the main SMJ line.

There are two ways to determine which of the four bridges that cross the Gayton parish cutting must have hosted this off-load installation. One is to consider the evident geometry in the photograph with some broad-brush dimensions extracted from the on-line Government Lidar survey data. The other is to simply walk through the entire cutting examining and photographing all four bridges from both sides - this proved to be very difficult and for some views impossible because of the virulent ivy which has covered the bridge parapets and facings.

Bridges    The bridges are highlighted in red in an inset below. Working towards the south:
1. A road bridge near the station, demolished and irrelevant.
2. Gayton - Blisworth road bridge. [It is actually labelled No. 3 in paint at track level]
3. Public footpath bridge ("Oxenfordwey") running east from Gayton Wilds farm (which is now a small estate of four or five private houses).
4. Private farmers bridge - a facility for Mr. Darker (c.1860) whose field was divided into two parts.
5. Saltway bridge - a road bridge continuing a re-routed connection between Tiffield and Gayton, also crossed by the Saltway.

In the historical records there is already evidence of a shoot (sic.) being once installed at road bridge No. 2. Only the box for the cart is shown in this diagram, arrowed in blue in the inset. The plan, dated 1905, was mainly to convey early 20th century changes to the tramway, blue crayon, that lies to the west of the cutting. It was copied and supplied by Barry Taylor. Perhaps this chute is the same one as depicted above but first consider the dimensions of the four bridges, as indicated in the Lidar imagery..

So for this "shoot" to work, an additional wooden chute would have been used which could connect the off-load arrangement at the top of the embankment with the wagons waiting below in a siding. If placed by any one of the 3 span bridges then it would have been about 20 metres long and sloped at about 30 degrees. No chute by bridge No. 2  is shown in the plan and so was perhaps taken away by 1905.

All the bridges with the exception of the private bridge No. 4 are similarly proportioned. The private bridge is located where the track is substantially level, ie. reached its maximum height before descending towards Tiffield at a point where the depth of excavation was at a minimum. A significant cutting, excavated by hand and barrow, extends for over a mile and this probably presented a problem regarding where the spoil needed to be taken.

Geometry    Photograph 18-09 tells us that the short piece of railway for the transfer trolley is near the same level as the camera lens. Given the man in the picture was about 1.8 metres tall, one can estimate that the road level is approximately 4 to 4.2 metres above the short rails. The camera tripod would be 1.5 to 1.9 metres high and standing firmly perhaps on a wagon floor which would be another metre from the track. These estimates yield a bridge height, road to track-bed, of 6.8 +/- 0.3 metres (and if the camera had been placed on the ground at more-or-less track level, this would bring the estimate down to only ~6 metres) suggesting bridge No. 4 as the likely location. Bearing in mind however that the angle subtended between the axis of the camera and either the bridge face or the track must have been in the region of 45° and knowing that common cameras c. 1900 could accommodate a field of view normally ranging over only from 25° to 50° the inevitable 'conclusion' must be that, for bridges Nos. 2,  3 and 5, the camera would have been floating in midair !

Expedition      First the bridges Nos. 2 and 5 were inspected at road level to help determine "where would the camera be located" and make some assessment of brick facings and copings. Then an outing, starting from the stairs at bridge No. 5, confirmed that No.5 was never the host for the chute installation because of brick and coping stones style and the fact that the side arch was much further away from the boundary of the cutting. Bridge No.4 was a reasonably close match at first sight. Some aspects of the brickwork on the north face matched well but it was largely covered in trailing ivy. The face was photographed but attempts made to achieve a good schematic fit with the historical image were unsuccessful. Brickwork colour (courses of black brick), copings and the shape of the arch were also a poor match. It seemed likely the brickwork was the original but the coping was built with corbel black bricks rather than slabs. The main problem in achieving a good match was because the single arch was very broadly elliptical.

Therefore my verdict was open until I could prepare an 8" shaving mirror attached with its swivel onto a 2 metre pole to enable a close examination of brickwork from above at the heads of the side arches in the 3 span configurations. There is no doubt at all that the verdict is the 18-09 installation was definitely at bridge No.2, just where it is drawn on the north side in the 1904 plan shown above. The camera angle relative to the bridge face was re-estimated to be about 37° when it was realised the bridge and its arch were considerable foreshortened. This had caused confusion over the horizontal distances between features. Referring to the diagram at the end of this article, the position and appearance of items A,C and D were in good accord. It appears that the parapet was rebuilt at some stage because the degree of out-sailing of courses at the base of the parapet was not a good match.

Regarding the camera position one must conclude that the stanchions or the struts for the wooden tramway bridge must have provided support at about the right height and that the photographer must have had access to a very long lens tube and struck lucky in regards to catching the dog 'frozen' enough for the inevitable long exposure. It is a shame the photographer did not record the rest of the chute and the equipment at track level that would have been necessary to control the energy of the descending rocks.

Other points are made in the Appendix.

Chutes     Finally we turn to a review of all the known off-load-to-railway installations along this cutting and the situation is shown in this third inset, based on OS 1899. Working from north to south each chute is identified by date (plans were kindly supplied by Brian Taylor):
    1905   a Wheldon application was to connect the tramway to the main line for the installation originally set up by George Pell, as mentioned above.
    "1885" - the date signifies 1865 - 1900. This is the "shoot", probably for Pell, marked at bridge 2 that has turned out to be the subject shown in image 18-09. It is drawn incompletely in the 1905 plan, therefore assumed in disuse by then although sidings on the west side are still in evidence in the 1905 plan.
    1888   an application for sidings on the east side includes an indication for a chute as marked which one assumes served the mining in the adjacent field (with/without a tramway?). Sidings on both sides of the main line are unlikely and it is probable that the north end of the siding did not actually reconnect with the main line. Interestingly, Tonks (p. 35) records that a later use of this off-load location was agreed with T. & I. Bradley (Darlaston) in 1912 and included a proposal to quarry a massive 200 acres but nothing came of the proposal. It serves to illustrate the 'state of flux' in ironstone mining that is now difficult to document.
    1881  another Wheldon application for sidings on the west side but showing no chute. Note that one of Tonk's maps show tramway sidings running near the cutting at this approximate location and a map referring to Wheldon's mining shows a tramway running close to the main line with a chute also marked. This is quite near to bridge No. 4 but not adjacent to it.
    Finally "?"   At a short distance north of bridge No. 5, there is some striking embankment disturbances that might have accommodated a chute. It is on the west side and marked in the inset plan at the point where Lidar indicate the disturbance. Perhaps this feature was connected with the management of spoil. Also notable in the Lidar data is a large 2 to 3 metre high embankment in the fields on both sides of the railway, between bridges Nos. 4 and 5. It is assumed this is spoil from the original 1860s railway excavation and perhaps intentionally limited to a collection of potentially useful iron-ore, with other burdens discarded. One might surmise that a possible chute here could have been used, at least initially, by the mining concerns to recover that iron-ore and send it north by railway. The existence of normal surface mining work in this southerly field has not been noted by Tonks. The landowner (The Darker family) recorded a feature labelled "Old Spoil Bank" on their estate map (1791) when it was updated in red ink to show the line of the railway but shows no access from the fields.

Whilst the arrival of the SMJ railway considerably inconvenienced the surface miners, it is clear that for a period that eventually extended to ~1950s the miners made good use of the railway in order to trans-ship to either the Grand Junction Canal or to the Birmingham to London main line. Records show that the relatively audacious overhead tramway used to work fields to the east just north of bridge No. 2 was in fact in place before the SMJ railway cutting was made. George Pell's sidings beneath that gantry once led to a tramway that served a siding beside the main line (a mile away). That tramway had to be moved to the west, out of the way of the cutting. Also, the gantry had to be rebuilt to cross the SMJ cutting, which is around 35 - 40 metres wide. The inset perhaps helps to visualise a timber construction using beams of up to 10 metres long. It was burnt down in 1929.

Reference: Eric Tonks, The Ironstone Quarries of the Midlands, Part III - p39 (but lacks detail at this level)

* the "SMJ railway" is more correctly named the Northampton and Banbury Junction Railway

Appendix:        The first picture shows the features in brickwork listed as testable item

The second demonstrates a recent picture taken through a hedge from a vantage point that was maybe 3 or 4 metres too high, at the edge of the cutting to the east and therefore from a considerable distance using a 200mm telephoto lens.

The bridge details are traced with coloured shapes in a separate Photoshop level and this level is then applied to the historical picture. All the details were in one geometrical plane and so neither of the 'vantage point' details, mentioned above, would have challenged the ability to morph the bridge details to fit the historical picture. It would appear that the parapet has been rebuilt 4 or 5 brick courses higher, the brickwork reveal was rebuilt nearly a metre towards the bridge centre and evidently there has been modifications to provide a more substantial buttress. All of this work was done once the loading "box" had been removed. Anyone reading this might be unconvinced and suspect the "right bridge" has not been found. There is only bridge No. 3 (Gayton Wilds) left to inspect in a thorough manner but it is covered in ivy (see view to the south at bridge 3) and there is an even poorer chance of obtaining a interpretable shot through the opposite bank hedge. If there is a bid for this work I can help with a map and a mirror!

I am forced to conclude that I was right in the first place: the camera was an ordinary one and was really in "mid-air" and there must have been a wooden bridge temporarily set across the cutting (perhaps part of the tramway bridge structure) on which the photographer could have stood. Basically, the 18-09 picture has too much perspective slanting of level lines for it to have been taken with a long lens.