Clear, Blaze & Survey

Clear and Blaze a Track for Surveying a Roadway

While it was probable that some of the army officers who were fulfilling the roles of surveyors and road engineers had knowledge of the road-making developments in Britain, one aspect which would not have come much to their attention was the environment in which they would be doing these developments in the new Colony. The large trees and heavy undergrowth on steep inclines of solid sandstone rock would have been quite outside their experience. In addition, it was not unusual in England for roads to follow valleys and wander alongside streams.They soon discovered that this was a route which led to huge sandstone cliffs in the new environment. Whether they learnt from following the tracks of aboriginal people or had gained some guidance from them, they found that the way across the mountains was along ridgelines. They would use valleys only when there was a way out to a larger river or stream, such as closer to the Hunter Valley.
It is not surprising that Thomas Mitchell had learnt to spend time on the highest outlook point he could find so that he could study the run of the ridges and valleys through his telescope for his choice of his "straightest way". This type of inspection has been mentioned earlier and it was really necessary for the country between the Hawkesbury and the Hunter Rivers. As people sought a route for the first time, they adopted the same procedure as aboriginal people had done for centuries before - they blazed their trail. A triangular section of bark, some 40 to 60 cm on a side, was cut from a large tree, facing the route line. The next blaze would be cut on a tree further along but in sight of the previous one so that gradually a path alignment could be seen connecting the blaze markings. On a new route, there would be no obvious pathway but at least one blaze had to be seen ahead. Aboriginal elders would sometimes use special geometric markings, understood by those educated in their customs, to show the way to them for their ceremonial events and for other special reasons. Where there were not enough trees to mark a track, cairns of stones would be used, perhaps less than 50 cm high, but in difficult terrain they might be up to one and a half metres high so that they could be seen over a longer distance behind undulations.

Reverend John Dunmore Lang had clearly become conversant with the markings and wrote in 1834, "Bush roads, as they are called, are formed by the person who first traverses the forest, notching the trees with an axe in the direction of the route, and the way to ascertain which of two doubtful tracks is the public road or a mere cattle track is to examine which of them has the trees notched along its course."

The Surveyors

Surveyors adopted the same approach:-

  • Assess where the road should go and clear a path ahead.
  • Blaze a tree and drive a peg into the ground where the road should go.
  • Send an assistant ahead to the next marker peg driven in and use a sighting to it.
  • Mark the line on the sheet on the plane table, estimate the distance up or down from the level table to the next marker and note it on the sheet.
  • Use a chain measure to determine the distance to the next marker peg, putting a stake in at each length of the chain.
  • Have an assistant collect each peg as the next is driven in.
  • Count the number of pegs and finally assess how many links and parts of a link in the chain to the last peg before starting all over again.
  • Write the distance in the log book and on the plane table sheet.
  • An assistant would be blazing the tree where the marker peg was driven in.

survey.gifThe assistant surveyors of the period seem to have developed their techniques for surveying in the difficult heavily wooded terrain of the country to the south and north of the Hawkesbury River. As men such as Heneage Finch and Percy Simpson became deeply involved, they learnt to cope with the local circumstances well and were able to cover quite appreciable distances each week of their operations. The progress was nevertheless slow and required backtracking over first routes to find better ones. There were setbacks too when the Surveyor General Mitchell and the Governor were not attracted to the route chosen as has been already mentioned.

Selecting the Line of Road

It is worth noting here some sections from a book by Edward Dobson on Pioneer Engineering (1877), in the chapter on Selection of Road-Lines. It was written well after the Great North Road construction but his references to the difficulties and choice of road-lines encountered in mountain range road construction are interesting. The comments reflect what must have been in Major Mitchell's approach to solving some of the GNR route problems.

The first operation is to find the point of the range to be crossed, taking barometer readings along watersheds to find the altitude of each point of observation. The next step is ascertain the distance from the foot of the pass to the summit on the ridge. This enables the effective gradient to be estimated approximately and thence to determine the most favourable ground to be used.

dobson_cross1.jpgHe draws attention to the situation that it generally happens that opposite sides of a range present very different conditions, a gradual rise on one side and a precipitous gradient on the other. In the latter case, it is necessary to determine the distance required for a practicable gradient by doubling the distance up the rise by forming zig-zags, remembering that the expense of making suitable turning places is very great with the additional length of road required being considerable. All turning places should not only be level but should be sufficient length for a time to halt on before turning. The plan is to select suitable spots for turning-places, and then to connect these binding points by the easiest gradient that the ground will allow. While this might mean some quite severe excavations, it is better than tight corners.

He gives a simple case in the figure where things have been "judiciously treated". In this figure, the turning places at a and b are on easy curves and on nearly level ground. If we take this example back into the past with Major Mitchell looking at how to go about getting up to the north from the Hawkesbury River, it is clear that Mitchell thought along the same lines that Dobson was advocating

Finch's Ascent v. Devine's Hill

finchasc2-2.jpgThe problems which confronted Heneage Finch and Percy Simpson in establishing a suitable way up the steep inclines on the northern side of the Hawkesbury River have already been mentioned. Construction of the road along the route surveyed by Heneage Finch in 1825 had been under way for some time before there was a visit to the area by Governor Darling and Major Mitchell in October 1828. It seems that they did not approve of the zig-zag route up the eastern slope of Roses Run, with the turns being far too tight for cartage to be undertaken safely. By courtesy of Ian Webb, we reproduce part of his map of Finch's Ascent up from the Hawkesbury River at the original Wiseman's Ferry crossing. The zig-zag line up the hill must have been what upset Governor Darling. The turning points were sharp and difficult for a cart drawn by horses or bullocks. Even each zig or zag had an appreciable gradient as well, perhaps 1 in 3 or 4. Just walking up the old roadway these days is quite a steep climb.

gnrwf1.jpgDarling instructed Mitchell to undertake a survey to determine a better line of ascent. Mitchell instructed Finch to investigate other lines of ascent in October 1828 on the western side of the ridge. Finch submitted two alternate lines in December 1828 but it seems that Darling and Mitchell did not approve of either proposal. Darling instructed Mitchell to "attend to the line of ascent himself". This he began on 17 January 1829 and he reported that "after some days of reconnaissance and making a survey, the line of ascent was found" to the east of land owned by Molly Devine, following the eastern side of a gully to the top of the hill and then eastward to link with Finch's line on the ridge. In the construction phase which followed, Mitchell measured the height of junction of the two road lines and recorded it as being 574.5 feet (175 m) above the River. No doubt he had used his barometer in just the same way during his reconnaissance of January 1829 to get the best gradients up Devine's Hill to meet the Finch Ascent road.

A present day RTA map developed for the Convict Trail Project gives a clear picture of the difference between the two routes which join together on the ridge above. From there onwards, the route was north but there were still some quite severe problems to be overcome.

When the decision was made by Mitchell to transfer all work to the Devine's Hill line of road, work stopped completely on the Finch Line. Mitchell had remarked that he anticipated that the Devine's Hill Ascent would be in operation within six months. In January 1830, Simpson reported that "the cart team may be able to go up the new line by Devine's Hill in about three months". Nevertheless, work was still going on on the new line and passage there would have been difficult and probably dangerous too. It seems probable that the Finch Ascent would have been used as that part of the road north until at least 1831 though there would have been incomplete or even unmade road from the top of the Finch Ascent to the new junction point with the Devine's Hill line.

Wiseman's Ferry

ferry1900a.jpgYou will have gathered that the ferry service operated by Wiseman was in existence at the time of the construction of the road to the north. It was rowed across the Hawkesbury and it is possible at some stage that there was a rope across as well. Drawings or paintings have not been found which give a clue to the original ferry.

Nevertheless, among some archival photographs from around the turn of the 20th century, there is a photograph of the ferry operating at that time, using a rope across the river from the same location as the modern ferry. The photograph has been taken from the north bank when the ferry was getting ready to move back to the south side. The ferryman appears to be getting into action on the rope system. The road up the slope and then to the west is the road which is now the main road along the north side of the river. With so much mention of Wiseman and his Ferry in these pages, we hope you will admire both this ferry and the view up the river at the turn of the 20th century.

Dobson, Edward, Pioneer Engineering, London (1877).
Newell, H.H., Road Engineering and its Development in Australia 1788-1938, Journal of the Institution of Engineers, Vol. 10, parts 2, 3 (1938).
Upton, T.H., The Establishment of Direct Road Communication between Sydney and Newcastle, Journal of the Institution of Engineers, Vol.4, parts 5, 6, 7 (1932).
Webb, Ian, Blood, Sweat and Irons, Dharug & Lower Hawkesbury Hist. Soc., p.32.
Convict Trail, Great North Road, A Set of 41 Maps, prepared by S. Lavelle, Dr G. Karskens and RTA Technology.

Clearing the Roadway after Surveying

With the line of the road set out by the surveyors, the major task of clearing at least one chain (20 metres) wide was begun. Lt. Jonathon Warner, one of the early surveyors we have mentioned, recommended that work and time could be saved by felling the large trees so that their heads pointed away from the line of road first of all. Large trees were cut down with a crosscut saws and felling axes. Convicts lopped off the branches and the trunks were cut into sections that would be rolled off the roadway with the use of bars and sheer effort.

Felling was done with a heavy axe which had an edge of about 7cm (2.5 inches) with the steel tempered to suit the hard timber which had to be cut. It had a large eye to take the robust handle. They were about six to seven lbs (3 kg) in weight. Crosscut saws were made with wooden handles at each end to draw the saw first one way by a convict and then the other way by the convict on the other end. It was usual to cut the tree off about 3 feet (1 metre) from the ground. The large trunk was sawn into lengths and rolled off the roadway.

Removal of the large stump was a considerable operation in its own way. The branches off the felled tree were piled around the stump, together with undergrowth and 'rubbish' so that the burn off would remove a great deal of the above ground stump and some roots. This would aid in the subsequent grubbing out of the stump still in the roadway. Assistant Surveyor Ogilvie emphasised in his weekly report that: ... extracting the stumps when all the timber has been burned off the line takes a considerable time, as timber has to be brought from off the adjoining land to the stumps for the purpose of burning them out. (NSW Archives Office)
The Weekly Reports from the Overseers are a useful indication of the disposition of labour on the road. A standard form was provided to overseers to indicate the type of employment, the number of men in the gang and their distribution among the tasks. Separate columns indicated the number of work in yards (length) and number of loads for moving materials. The final column listed remarks on various matters by the overseer. On Tuesday, 13th January 1829, J. O'Hara as Overseer of No. 9 Iron Gang set out the following work done: Quarrying Stone 4, Breaking Stone 3, Rolling Stone 6, Clearing Quarry 3, Building Walls 3, Carrying Water 4, Barrowing Rubbish 2, Repairing Tools 2, Falling Timber 5, Clearing Road 8, Sawyers 2, Bullock Driver 1, Stripping Bark 2, Splitting Rocks 2.
Of O'Hara's Gang at this report time, there were only 47 convicts who were at work on the road, out of a total of 71. The five mentioned specifically on the form were one overseer, two assistant overseers, one hutkeeper, one stock-keeper and there were four convicts in hospital. In the handwritten items, there were 10 absentees, though it is not made clear where they were and there were 5 in court on misdemeanours of various kinds, including absconding and being recaptured. The remarks on the copy of this report are not very legible so it is difficult to determine what problems O'Hara had had in that week. The report went to Major Lockyer J.P., Surveyor of Roads and Bridges. (NSW Archives Office Reel 590). We will refer to these reports again later where other tasks are mentioned.
Reference is made in some of the reports from the Assistant Surveyors, such as Percy Simpson, to the employment of artisans from the Department. These included blacksmiths, toolmakers, carpenters and sawyers. It was probable from the context that these men were specialists in their fields, giving support to the Assistant Surveyors and Overseers in training convicts to undertake such work on the roads. It is not evident whether these artisans were free men or convicts who had Tickets of Leave, Pardons or had worked out their time. It will be an interesting topic to pursue further.

Reports by Assistant Surveyors

psimpson.jpgEach month, Assistant Surveyors prepared their report on the activities of the Gangs under their charge, in addition to their weekly reports. It was not unusual for a letter to be forwarded with the monthly report, respectfully to beg leave to call attention to observations under the head of a particular Gang.
Percy Simpson seems to have been adept at putting his recommendations and requests for action into such letters. The report in some cases was not just a list of men employed on various tasks. It detailed work that was under way, problems that had occurred (for example, during his one week absence for criminal proceedings at Windsor), shortages of supplies (particularly tools and blasting powder) and delivery of rations to prisoners by contractors (Mr Wiseman in particular). In his report for January 1830, submitted with a letter to the Surveyor General on 10 Feb 1830, there are clear indications that Simpson must have had real problems, coping with all the gangs under his charge and getting essential work progressed expediously.

Harvesting and Return to Road Gangs

His road gangs were reported to include No.4 Iron Gang (49 men), No.25 Road Party (90 men), No.3 Gang (35 men), No.8 Iron Gang (57 men), No.9 Gang (31 men). The extent of the work is well revealed in the January 1830 report. Government Regulations required that prisoners be lent to farmers around the area to assist with harvesting. Harvesting groups were only allowed to be made up out-of-irons convicts from road parties. They performed these duties over a period of around six weeks during November and December each year. January was the month when they were returned to their Gangs and were again working on the road. Each had its Overseer but these gangs were working in places along the line from Devine's Hill ascent to Snodgrass Valley and Giber Gunya, making contact between them difficult for Simpson. Reliance on the Overseers controlling the groups was thus essential to the effective continuation of his responsibilities.
76 prisoners were returned to No.25 Road Party after the harvesting and others were added so that by the end of January 1830 the total strength was 90. [Ref. 1] The 90 men in No.25 Road Party was in excess of the permitted number in one such road party. As a result, Simpson detached a group of about 15 convicts and sent them under Assistant Overseer Arnold Clare to Snodgrass Valley. Clare is a man who will appear again as the overseer of a remarkable Bridge Party.

Men Out-of-Irons

From reports such as this one and the weekly reports, Ian Webb in Blood Sweat and Irons [Ref. 2] has been able to summarise the number of men in-irons and out-of irons in the year 1830. He concluded that No.3, No.8 and No.9 Iron Gangs averaged from seven to nine men out-of-irons. These would have included the principal overseer, one or maybe two assistant overseers (depending on the size of the gang and the extended area of the works), the clerk, a messenger, a hut keeper, a cook, a stock keeper in some cases, a bullock driver and water carriers. In some places, the number of out-of-irons men might increase to undertake essential operations, such as blacksmithing and the management of a hut which was used as a hospital and dispensary by an assistant surgeon.

Tasks in January 1830

Simpson reports that part of No.25 Road Party had been employed excavating an approach (from the side of the Mountain) to the Bridge on the Line of Road running parallel to the North Shore of the River [Hawkesbury], widening the Road in places where required leading to the Bridge and side cutting and quarrying beyond and northward of the same. The Bridge to which he refers is the bridge which still remains in use on the north side of the River, to the west of Wiseman's Ferry, just before the road turns north up Devine's Hill. He goes on to report: Others of the Party have been employed digging a Foundation for a side wall and in blasting and removing some extensive overhanging Rocks wherefrom the requisite width of the Road must be taken. The expenditure of Gunpowder has been 30 Pounds during the month. In this latter part of the report, he is likely to have been referring to a support wall for the roadway where the ground fell away steeply down to the River, just prior to the turn to the right up the main section of the Devine's Hill Ascent.

He reports also that 24 prisoners were transferred from No.3 Iron Gang to No.8 Iron Gang where they could be more advantageously employed in the absence of a sufficiency of quarrying Tools. A side note on this copy of his report indicates that his requisition for more tools had been noted. The transfer of men must have been rather necessary. Part of the Gang so transferred had been occupied in filling an extensive Hollow near 7 Mile Post and building side walls therein.

A Very Stupid Error

stupid.jpgThe other portion of the Gang were cutting and forming the road for the descent into Snodgrass Valley. It was during this period that Overseer Ashford committed a very stupid error by deviating from the Line repeatedly pointed out to him and marked, which he was ordered most strictly to follow so as to unite the descent with the line of fallen timber in the bottom of the Valley. Afterwards the Overseer undertook on his own responsibility (to hide his mistake) to fall another Line running nearly parallel with the former one (which had been commenced) as far as the Water Holes. For which neglect or carelessness I beg leave to recommend his being [denied] of the present quarters Salary. He has been permitted to remain in charge of the Gang ... The side note says "certainly". There was a serious loss of time as a result and Ashford must have been made to feel the impact of the decision. The addition of 25 prisoners, transferred to the Gang, was done with a view to expediting the additional work which the Overseer's conduct or neglect had rendered necessary.


In coping with all these problems, Simpson had further difficulties with prisoners absconding in these rather remote areas. His report notes that 8 prisoners absconded from No.4 Iron Gang, 2 were summarily tried from No.25 Road Party and transferred to Iron Gangs, 8 absconded from No.3 Iron Gang, 6 absconded from No.8 Iron Gang but 3 were recaptured and put back in the Gang, and 14 absconded from No.9 Iron Gang. In this latter group of 14 absconders, 6 were recaptured and received back, one was received back from Hospital and 7 were summarily tried (no sentence given). There were obviously quite a lot of prisoners who were prepared to try absconding, but not getting far very often, and sometimes even finishing up in Hospital.
In summarising this situation, Simpson writes: The discipline of the Prisoners considering the Character congregated is maintained by the Overseers to the best of their ability but at this Season of the year it is impossible to prevent their absconding which has occurred to rather an unusual extent particularly from among the new Committments to Iron Gangs.

Comments in January 1830

The final comment in the report could have been rather too hopeful or has been perhaps misinterpreted to mean that the road up Devine's Hill would be open for business as stated: I anticipate, if there should be no delay in procuring a fresh Supply of Powder when that now on hand is expended, that a Cart-Team may be able to go up the new Line by Devine's Hill in about three months. There are many Holes prepared for blasting and in the month of February a great Expenditure of Powder will be necessary. Balance of Powder in the Store the 31st January 1830 - Three hundred and Eighty Pounds. He was envisioning the great quantities of rock which were to be blasted out of the eastern side of the mountain and a wall of over 10 metres height that had to be constructed.
It is possible that Simpson meant that a Cart-Team could go up the new Line for his purposes. Nevertheless, whatever he meant, that road was not open to general traffic for at least two years thereafter, not three months. He would certainly have need good access for the enormous quantities of material that had to be shifted in the form of timber, excavated and loose soil, loose, quarried and blasted rock, moved and converted into stone blocks for walling.

Other 1830 Monthly Reports

In his January 1830 Report alone, the work on the Devine's Hill Ascent had begun in earnest. No. 3 Iron Gang were involved in the massive operations of widening the road, blasting, quarrying stone blocks and preparing the foundations of a transverse wall.

Ian Webb (Ref. 2) has drawn together an amazing selection of the work from the weekly and monthly reports, done by Iron Gangs and Road Parties. In particular, No.3 Iron Gang carried out the following work: By March 1830, it was reported that over 40,000 cubic feet of stone blocks were prepared (i.e. something in the order of 3,000 tonnes of stone), transported and laid on this foundation over a length 300 feet, 12 feet high and 12 feet wide. It seems likely that this must have been at an early stage in the construction of the wall with its buttresses on the way up Devine's Hill. In May 1830, 66 men built 70 yards of wall, nine feet high, blasted away 260 tons of rock, quarried 200 tons and removed 3,000 barrows of gravel, expending 130 pounds of gunpowder in the process. September 1830 saw the gang down to 40 men: They built a further 94 yards of wall one yard high, filling behind the wall to keep level with the height built. They blasted away 180 tons of rock, quarried 300 tons, broke down and carted 40 tons for filling behind the wall and moved 2,400 barrow loads of gravel. Webb finishes that extraordinary listing of effort by noting: During the month one man was found dead; no details are mentioned. And finally, he notes that No.3 Iron Gang continued working on Devine's Hill until the works were completed in 1832, and comments: Unfortunately, very few records survive for the period 1831-1832 due to the transferring of the Roads and Bridges Department to the Surveyor General's Department.

What a story those records could have told!

1. NSW Archives, Road Gang Reports 1827-1830, Reel 590. 2. Ian Webb, Blood Sweat and Irons, pp.41-2: Dharug & Lower Hawkesbury Historical Society, 1999.


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