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The Deep Cut scene has been populated with laborers drilling, chipping, and hauling rocks. Only two figures remain to be added. Both will represent real people.

In 1822 the four original Mountain Ridge contracts were subdivided into six contracts. The contract for Section 3, which commenced one mile south of the locks, was awarded to a local landowner named Darius Comstock.

The Comstocks, a family of Quakers from Massachusetts, had recently settled in Farmington, southeast of Rochester. Like many other newly arrived Yankees, several members of the family were restless to move further west.

An opportunity presented itself as land went on sale in the Holland Land Purchase west of the Genesee River. Nathan and Zeno Comstock purchased parcels in a sparsely settled area near Eighteen Mile Creek. This was a stroke of good fortune, for that very spot – which surveyors would soon designate as the place where the Erie Canal would ascend the Mountain Ridge – would become the village of Lockport.

Other members of the Comstock family joined them, including Darius, who, once canal construction began, would submit his bid for Section 3.

Besides being a pioneer, a savvy land speculator, a pillar of the community, and abolitionist, Darius Comstock was also, apparently, an inventor. A list published by the government in 1840 records a patent issued to him in March, 1825, for an “excavator.” What it looked like, and how it operated, will probably remain a mystery. Any records filed at the United States Patent Office would have been destroyed in the December 1836 fire (along with the records for Orange Dibble’s crane and many other early American inventions).

Whether Darius Comstock made use of his patent is not known. His section of the Deep Cut had been completed the year before. By 1825, even before the Erie Canal was finished, his attention was diverted further west, yet again. Soon he would relocate to help establish a new Quaker community in Adrian, Michigan.

Nathan Roberts, who in 1822 was put in charge of the canal between Lockport and Buffalo, had no formal training in engineering. In this regard he was no different than any of the other Erie Canal engineers. Every one of them learned their profession on the job.

Roberts had started his career as an itinerant mathematics teacher on the New York frontier. In Whitestown, where he taught school, he no doubt was very familiar with water navigation on the nearby Mohawk River. One of his students was Canvass White, who also would become an Erie Canal engineer.

Hired by Benjamin Wright to take part in the initial 1816 canal survey, Roberts’ gift for mathematics would continue to open doors. He quickly rose in the ranks of the fledgling engineering corps and is best remembered as the designer of Lockport’s iconic “Flight of Five” staircase locks.

Later, as a graduate of the “Erie Canal School of Engineering,” Roberts would take charge of other civil engineering projects, including a new railroad bridge over the Potomac River at Harper’s Ferry.

Designing the characters

Apparently there are no surviving images – paintings or silhouettes – of Darius Comstock, so I was free to make my own interpretation of how he may have looked. We do have a painting of Nathan Roberts, done some 20 years after the canal was built.

The clothing they might have worn is open to conjecture. For the purposes of the illustration, I’m assuming that, as successful men, they would have dressed the part. Though as a devout Quaker, Comstock would have worn clothing that was somewhat more plain.

But not homespun. Despite its location on the New York frontier, Lockport now was connected to eastern markets by the canal, which was navigable from the foot of the locks all the way to New York City. Items that previously would have been considered luxuries – including fine fabrics – were arriving daily.

As for Roberts, well, as principal engineer he probably wore the three-piece suit of the day – pantaloons, waistcoat, and frock coat. And a top hat, of course, which in the early 19th century was considered de rigueur.

Fortunately, several 19th-century tailor’s guides – from The Taylor’s Complete Guide to The Tailor’s Friendly Instructor – have been digitized are are available online. The patterns they include are not like today’s patterns; they are really measuring guides. But (after some study and more than a little head-scratching) they can be picked apart and adapted.

Using Marvelous Designer, a CAD-based software application, the patterns can be cut out, stitched together, and fit to the human character models. The program then handles the clothing simulation, taking gravity and fabric characteristics into account. The clothed characters are then moved into Terragen and shaded.

I’ve been using Marvelous Designer for a while now – all of the laborer’s clothing in the scene are variations of the same simple work shirt and trouser patterns – but these more upscale outfits were a challenge. It’s given me a much greater appreciation for anyone who works in the garment industry, especially designers, dressmakers and tailors. It’s a good thing my rough efforts are strictly digital.

One of the most enduring myths about the Erie Canal is that it was built by Irish immigrants. In fact, the majority of its 363 miles were contracted out to and dug by native New Yorkers. In their 1819 report, the canal commissioners had proudly reported that “three-fourths of all the labourers” working on the canal “were born among us.”

But there are many reasons why the tale of Irish workers has been so persistent.

To begin with, by the commissioners’ own account fully one-fourth of the laborers working on the canal during the first full year of construction were immigrants. While that group would have included people of many nationalities, most probably came from Ireland. As work progressed that number grew until Irish workers predominated along certain sections of the canal.

Those sections were among the worst places to work along the line. They included the Cayuga Marsh, the Great Embankment, and the Deep Cut. Native-born Americans, it seems, were more than willing to leave the dirtiest, most dangerous work to the latest arrivals.

Predominantly young, male and single, the Irish brought from the old country entrenched notions about masculine behavior, a strange religion, and a stranger language. They soon earned a reputation for fighting, which “native” Americans attributed to the bottle, because the Irish had a reputation for that as well.

By all accounts, they were a rough bunch.

But antebellum American society already was violent, especially along the frontier. Americans of all classes, to put it mildly, drank like fish.

But the stereotypes became excuses to keep the newcomers in their place. In Lockport they were relegated to drafty, squalid shacks along the excavation and in “Lowertown,” while established citizens maintained a prosperous, middle-class existence in the “Upper Village.”

The Irish workers’ reputation for violence and drink may well have been exaggerated. We will never know for certain, because the workers themselves and their families, for the most part, were illiterate and left behind no records.

But when all was said and done, the Irish and other immigrant workers completed the tough, miserable task of excavating the Deep Cut. They dug, and drilled, and died — in explosions, from falling rocks, from disease. Over four long years they chipped and blasted their way through the Mountain Ridge, overcoming that final obstacle to open the canal from Buffalo to New York City.

Populating the scene

In his book, Stairway to Empire: Lockport, the Erie Canal, and the Shaping of America, historian Patrick McGreevy uses surviving expense vouchers to estimate the crew sizes for several contractors working in the Deep Cut. He calculates an average crew size of 94 men, yielding a total workforce of 2,068 for the 22 contracts that were active through July 1824.

This is a larger figure than the 1,500 men mentioned in Colden’s Memoir. Regardless, the size of the workforce was unprecedented in this country.

Because the excavation on the Mountain Ridge had been going so slowly, New York in 1822 assumed direct supervision of all of the contracts there, turning the contractors into middle managers paid by the state. More workers were recruited and others shifted to the summit from other sections of the canal to achieve this remarkable concentration of labor.

McGreevy’s estimate gives us a good idea of the number of workers that will be needed for the Deep Cut scene. It depicts a single contract, so we’ll need about 100 human models.

Of course, we don’t need 100 unique models to accomplish this. Duplicates can represent groups of workers, especially in the distance. To figure out the number of models that would be needed, I put together a simple mannequin model and used it to quickly make a series of poses, eventually winnowing the number down to about 20.

The selected mannequins were placed in the scene. This eliminated a lot of guesswork and helped to create a list of figures needed, their poses, and locations. After that it just became a matter of setting up a pipeline to produce the actual human models. This post includes a test renderings of a few that have been completed, and more are on the way.

This is just a quick update, a pause to take stock before starting final work on the Deep Cut scene.

The terrain itself is complete, aside from a few minor adjustments and tweaks. The horse and driver models have been placed and provide a sense of scale. Other models will be added over the next few weeks — a few workers to man the cranes, and many more on the floor of the cut. Plus a contractor and perhaps a chief engineer.

I keep thinking of that description of the excavation in Cadwallader Colden’s Memoir, which reads in part:

“Each of these cranes formed a heap of rocks, . . . and when in full operation for three miles in length, and the work progressing under the hands of fifteen hundred men, under a continual cloud of smoke, and almost incessant explosion of rocks, produced a novel and interesting scene.”

When all is done — and there remains much to do — I hope that the finished picture will convey the same sense of scale and wonder.

The workers who excavated the Erie Canal used primitive tools: picks, shovels, and bars – long crowbars used to pry loose layers of rock. A laborer from the Middle Ages or even ancient Rome would not have felt much out of place in the Deep Cut in 1824.

They would have noticed one change, however, which was the use of black powder to blast through the solid rock. Black powder had been used for mining since the early 17th century. However, blasting – or “blowing,” as it was commonly called then – was haphazard and extremely dangerous despite nearly two hundred years of practical experience.

Many Erie Canal contractor receipts preserved in the New York State Archives include entries for powder, which would have been purchased from nearby wholesalers in 12 ½ or 25-pound kegs. “To 9 cages [kegs] of Powder for blasting out Lock bottomes on Erie Canal at four dollars and fifty cents per Cag,” reads one dated May 22, 1824, while another enumerates “116 Kegs Powder of Hubbard and Parsons at $4.50 pr k.” Along with labor and whiskey, it seems, powder was one of the contractor’s most significant expenses.

The powder used at Lockport was manufactured by Éleuthère Irénée du Pont at his gunpowder mill near Wilmington, Delaware, and was formulated specifically for blasting rocks.

Black powder was used because the excavation of the Deep Cut preceded the invention of dynamite. It also preceded (by many decades) the invention of pneumatic power drills. Instead, a forged steel drill was held in place by one man while another pounded it with a sledgehammer, rotating it a quarter turn between each blow. If this sounds tedious, it was – as well as dangerous for the fellow holding the drill, who risked getting his arm smashed if the hammer missed its mark. Probably not an uncommon occurrence given the amount of whiskey the workers would have consumed in any given day.

Legend has it that workers were stymied by the hard rock of the Deep Cut, which blunted their drills, until a local blacksmith named Botsford stepped forward with an improved process for forging hardened steel. His drills, which featured a diamond-shaped tip, enabled the work to go forward.

I haven’t been able to confirm this account. It appears in newspaper columns and several popular histories, but none cites a source. Botsford, who never seems to possess a first name, is variously described as being from Niagara Falls, Buffalo, or Lockport. But he is mentioned in none of the primary documents that I’ve checked, and there are no patents attributed to him. So either the story’s details have been lost to history or, at some point, it was simply made up.

Or maybe not. The Erie Canal Discovery Center in Lockport has a Botsford drill in its collection. Its provenance has never been documented, but it fits the historical description. Even if it isn’t actually from the period, it most likely is similar to the drills that would have been used. The drill model I’ve made is based on it.

The drills would have been used to create holes about two feet deep in which a quantity of powder would have been placed and fused. The process was carried out by “blowers” – often inexperienced and untrained workers. As part of the masculine culture of the canal workforce, these men took pride in exposing themselves to danger and (it’s worth noting again) consumed large quantities of whiskey on the job. It was an unfortunate combination, and the result was entirely predictable.

Many years later “Aunt Edna” Smith, one of the original inhabitants of Lockport, recorded her memories in the “Recollections of an Early Settler,” which was published in five parts in the Lockport Daily Union. In one installment she described the process of blowing rock:

“Many accidents occurred from the carelessness of the man in the use of powder, such as staying too near the blast at the time of the explosion, &c. If the fuse went out or burned slowly, they would rush back recklessly, to see what was the matter, often blowing them to revive the dying fire. Many a poor fellow was blown into fragments in this way. On some days the list of killed and wounded would be almost like that of a battle field.”

And the hazard wasn’t confined to workers:

“The blasting of the rocks for the foundation of the Locks, and the canal above, was a constant source of danger and annoyance to the inhabitants.

“Stones several inches in diameter were daily thrown over into Main street. When the warning cry of “Look Out!” was sounded for a blast, every one within range flew to a place of shelter. The small stones would rattle down like hail, and were anything but pleasant, particularly when one was caught with uncovered head. One stone weighing eighteen pounds was thrown over our house, and buried itself in the front yard.”

As historian Patrick McGreevy points out in Stairway to Empire: Lockport, the Erie Canal, and the Shaping of America, “Mrs. Smith’s home was more than seven hundred feet east of the Deep Cut.”

The shovel model for the scene is based on a shovel on display at the Erie Canal Museum in Syracuse, New York. The museum’s example dates from the 1830s and is clearly a frontier artifact, with a composite blade made from hardwood and forged iron. It’s not easy to imagine someone laboring 12 to 14 hours a day, excavating hard soil and broken rock, with this primitive tool.

Workers at the Deep Cut and elsewhere on the canal would have hauled excavated rock and soil with the Brainard wheelbarrow, a revolutionary new design patented in 1819. The wheelbarrow, which used curved planks of wood for the tray, was significant enough to warrant a mention in the canal commissioners’ 1820 annual report: “Mr. Jeremiah Brainard of Rome, has invented a wheel barrow, which, without being more expensive than those in common use, is acknowledged by all who have seen it to be greatly superior to them. Its advantages consist in its being lighter, more durable, and much easier to unload.”

My wheelbarrow model is based on a surviving example from the 1830s on display at the Erie Canal Park museum in Camillus, New York.

The Deep Cut was a man-made artifact that sliced across the landscape of western New York. At the time, many people saw it as a work of “art” that improved Nature for the benefit of all.

But even though Nature was “improved,” it wasn’t completely overcome. The waterlogged terrain that constantly threatened to flood the work, the dense forest, and most of all the layer upon layer of tough dolomite resisted the incursion and made life miserable for the engineers and workers struggling to execute the great work.

Little was spared in the effort. Great quantities of black powder and whiskey – and an untold number of lives – were consumed as the cut inched forward.

The result was a pre-industrial industrial landscape.

Orsamus Turner, an early settler and newspaper editor, recalled the scene in his Pioneer History of the Holland Purchase of Western New York:

“The dense forest between Lockport and Tonawanda creek looked as if a hurricane had passed through it, leaving a narrow belt of fallen timber, excavated stone and earth . . . The blasting of rocks was going on briskly, on that part of the canal located upon the village site; rocks were flying in all directions . . . and huge piles of stone lay upon both banks of the canal . . .”

This would have been 1822 as work was just beginning. The blasting and huge piles of stone would extend along the entire length of the cut as work continued through 1825.

Digging up the dimensions

As I began to put together the landscape for this scene, my first question was pretty basic: What were the dimensions of the cut?

Surviving records from the original construction period are sparse. We have the annual reports of the canal commissioners, letters from them and the supervising engineers, some early surveys, and some contracts and receipts. To the best of my knowledge there are no engineering plans as we understand them today.

This was art, after all, created by artisans. In the pre-industrial era masons and carpenters drew upon their visual imaginations and years of experience and not much else. Locks, dams, weirs, and so forth were built from memory or perhaps by referring to sketches that were quickly discarded. It was an effective way to work, and the structures that remain attest to the care and pride they took in it.

This soon changed. The industrial era – introduced to some extent by the canal itself – required bureaucracies, trained engineers, and armies of surveyors, clerks and draftsmen. As planning for the first canal enlargement began, they got to work.

The New York State Archives in Albany has several volumes of contracts and estimates, one of which was completed in the late 1830s for enlargement work along the Deep Cut. I’m grateful for the help provided by the archivists who tracked this down.

The volume contains hundreds of precise cross sections used to calculate the exact amount of soil and rock to be removed for the enlargement. To make them, surveyors measured the prism at intervals of 66 feet (one chain) all the way from Lockport to Tonawanda Creek.

The measurements confirm the maximum depth of the original profile, about 32 feet, mentioned in the canal commissioners’ annual reports. They also include the channel width and the size of the ledge for the towpath. The channel is narrow, about 31 feet, just wide enough to allow two canal boats to pass. The towpath is 10–12 feet wide, just wide enough to allow two teams of mules or horses to pass.

Apparently, the original engineers did not want to blast a single unnecessary cubic yard of rock.

Constructing the surface

The depth of the cut, the vertical walls, and the number of lateral (sideways) displacements make this a difficult landscape to model. After a couple of false starts I used an approach suggested by Ulco Glimmerveen on the Terragen user forum. This approach uses a few large primitive shapes – three cubes and a plane – to set up the basic surface, along with the rock pile shapes described in an earlier post.

The rock walls required more experimentation. Excavated dolomite resembles shale but has thicker layers. Later historical photos (like the one included at the top of this post) were a big help here. (Photos of the original excavation, of course, are nonexistent – photography hadn’t been invented yet.)

The rock wall was the biggest challenge, and was finished first. The floor of the cut and towpath, both partly flooded, came next, and layers of rubble were scattered pretty much everywhere. A few variations of the Dibble crane were included as placeholders (more will be added later). Thick, turbulent clouds convey an ominous mood (and help scatter the light into the shadows). A plume of dense smoke from blasting can be seen in the distance.

Despite some natural relief provided by the edges of the forest on either side, the picture so far has a dark, gritty look that seems appropriate.

The most striking objects in George Catlin’s lithograph of the Deep Cut excavation are, of course, the horse-powered cranes. Arranged on each side of the cut, the repeating, angular shapes make a dramatic pattern against the sky.

The lithograph, along with additional scenes of the canal by Catlin and other artists, was printed in Cadwallader Colden’s Memoir, published in 1825 to commemorate the opening of the canal. The image and its descriptive text, included in an appendix, are our primary source of information about the machines.

“The cranes,” the writer reports, “are an ingenious application of mechanics to a horse power, enabling him to raise a ton weight or more from the bottom of the Canal, and discharge it in huge piles at a distance of sixty or seventy feet from the excavation, and fifty feet above its banks. They were generally set at regular distances from each other, (sixty or seventy feet) and fifteen or twenty feet from the Canal, allowing the extremity of their gibs to describe about to the middle of the chasm.”

After spending another paragraph or two describing how they worked, the writer adds (with some degree of understatement) that the cranes, “when in full operation for three miles in length, and the work progressing under the hands of fifteen hundred men, under a continual cloud of smoke, and almost incessant explosion of rocks, produced a novel and interesting scene.”

The machines were the brainchild of Lockport contractor Orange Hezekiah Dibble. Aside from the text in the Memoir, detailed information about his invention is hard to come by.

The canal commissioners’ annual reports to the state legislature – generally expansive when describing new technology, especially when it was inspired by the canal – are silent about the cranes, though Orange Dibble is listed as a contractor.

There is no patent application or drawing. Any that existed would have been destroyed in the fire that swept through the patent office in December 1836. But we know that a patent was issued. A list published in 1840 includes one for an “Earth, removing” machine awarded to Orange H. Dibble of Niagara County, N.Y. on February 20, 1824.

Two months later – April 1824 – this notice appeared in the Lewiston Niagara Sentinel:

“Fatal accident — David Gilroy, a laborer on the canal, was killed near this village on Friday last. He was engaged with a number more in excavating rock with a machine which is worked by horsepower. The box appertaining to the machine had been filled with stone amounting probably to 1,000 pounds, when after being raised to the height of 30 feet directly over the head of the unfortunate man the chain by which it was suspended broke and the box and contents fell upon him and killed him instantly.”

Apart from reminding us just how very dangerous canal work could be, this brief item confirms that at least one of Dibble’s machines was on the line early in the 1824 construction season.

Finally, there is one more very reliable source.

“Of the crane I enclose a figure”

Increase Allen Lapham was born in 1811 to Seneca and Rachel Allen Lapham of Palmyra, New York – a backwoods village that later would become a stop on the Erie Canal. His father was a contractor who specialized in canal construction. His family followed work as it became available and was constantly on the move. 

In 1818 they relocated to the Schuylkill River in southeastern Pennsylvania. Two years later they returned to the town of Galen in western New York, just a few miles away from the Erie Canal, then under construction. In 1822 they moved on to Rochester. Increase and his older brother, Darius, covered the 30-mile distance on foot, driving “a cow & calf,” as Increase later noted in his diary. In Rochester, Seneca Lapham worked on the aqueduct that would carry the canal over the Genesee River.

In 1824 the family was in Lockport, where Seneca built lock gates and bridges. Young Increase labored on the canal as well, writing that he “cut stone for the locks sometimes & earned $1 per day.” But he and his brother were soon moving up. “We have got acquainted with Mr. Alfred Barret the Engineer of the canal & Darius got employment under him — Soon after I was also employed at $10 pr month & $.50 per day for subsistence.”

Increase was extremely bright and quickly began to soak up the basics of surveying and canal engineering. He was also observant and took note of everything having to do with canal construction on the Mountain Ridge, including Orange Dibble’s cranes.

By 1827 the family had moved yet again, this time to Shippingport, Kentucky, where the Louisville and Portland Canal was being constructed around the Falls of the Ohio River. It wasn’t long before Increase was handling much of the company’s bookkeeping.

The Louisville canal included a difficult rock cut much like the one at Lockport. Cranes like those used on the Mountain Ridge were being built and pressed into service. Sixteen-year-old Increase, now an assistant engineer and an accomplished draftsman, made a drawing of one of them. He sent the drawing, along with an article that he had written about the construction of the Louisville canal, to Professor Benjamin Silliman of Yale University for publication in the American Journal of Science and Arts.

“The excavation of rock is done by drilling, and blasting,” Increase wrote in the article, “and is afterwards removed from the canal, by the use of a crane of the same construction as those used on the mountain ridge in New York, invented by Mr. Orange Dibble. Of the crane I enclose a figure.”

Increase Lapham stayed with the Louisville canal until 1829. Eventually he made his way to Wisconsin, where he became a naturalist and cartographer. He died in 1875 and today is revered as the state’s first great scientist.

Orange H. Dibble continued to do contract work for a few more years and became postmaster of Buffalo, by then a boomtown because of the Erie Canal. Eventually he, like so many others, was swept up by the Gold Rush and moved his family west. He became one of the original pioneers of Grass Valley, California, and operated a sawmill in nearby Gold Flat. He figured prominently in the state’s Masonic organizations until his death in 1864.

George Catlin went on to fulfill his dream of painting Native Americans, and spent most of the 1830s traveling throughout the American West. Later he took his “Indian Gallery” on tour in the eastern U.S. and Europe, where he turned out to be as much of a showman as an artist. After returning to the states he was forced to sell the gallery to pay off personal debts. Today the collection – more than 600 works – is part of the Smithsonian American Art Museum. Catlin died in 1872.

The cranes themselves, thanks to Catlin, have achieved a permanent place in our imagination and the mythos of the canal’s construction.

At the time, they were a rough-and-ready solution to a simple problem: How to get rid of the broken rock from the bottom of the ever-deepening Deep Cut. Lockport was an isolated outpost surrounded by forests and swamps. The pioneer contractors working there had to make do with local materials, and timber was plentiful. 

The resulting machines were primitive and dangerous, but apparently they did the job. It’s been said that they speeded up completion of the Deep Cut and the canal. Perhaps. But by the time they appeared on the line in 1824, perhaps late 1823, much of the excavation was already done. Maybe the problem wasn’t one of time, but space: Once the channel reached a certain depth, wheelbarrows and ramps became impractical and another solution was called for. 

Modeling the machine

Catlin’s cranes are the work of an artist: fleeting, energetic and alive, they nevertheless contain very little practical detail. Which is why I’m so grateful to have found Lapham’s drawing, which was the work of a budding engineer. All of the details that we need to know about the machine are there with one exception: scale.

The ghostly, pencilled human and horse figures in Lapham’s drawing give us some idea of how big the cranes were, but determining a reasonable scale still took some experimentation. The placement of the cranes at intervals of 65–70 feet – as specified in the Memoir – was one factor, as was the need to provide enough room for the piles of stones.

For now, I’ve settled on a machine that’s 30 feet high, with a mast of 25 feet and a horizontal reach of 34 feet. The diagonal jib is about 45 feet long. The contractors who built the machines would have been felling a forest of old-growth trees – sugar maple, beech, oak, ash, and elm – so obtaining beams this size should not have been a problem.

It’s a simple machine and the model comes together quickly. We’ll make many variations to insert along the cut in the scene. Final details – including horses to provide power and teams of workers – will be added once the cranes are all in place.

A few details need to be nailed down before we can set up the Deep Cut scene. Some, such as the width of the cut, should be recorded somewhere in the historical record. Other details, like the size of the rock piles, can be calculated.

I’m still looking for a source on the dimensions of the cut. In the meantime we can start on the rock piles.

How tall were they? Contemporary sources describe them as “huge,” achieving heights of up to 50 feet.

Perhaps, but let’s see what a little math tells us.

When it comes to excavating stone, there are two important numbers: angle of repose and swell factor.

Angle of repose is the slope at which a pile of stone (or any material) remains stable. At a greater angle, gravity will overcome friction and the material will slide down the slope. For dolomite and broken rock, the angle of repose varies between 35 to 40 degrees. For now I will use the minimum angle of 35 degrees.

This makes it simple to calculate the size of a cone of broken stone 50 feet high. A 35-degree angle of repose yields a base diameter of about 143 feet.

As the tiny human figure standing next to the cone shows, this is a very large pile of rocks. Much too large based on the size of the canal cut shown in the adjacent profile. In fact, a cone this size would contain more than five times the amount of rubble that would be excavated from the cut. The crane needed to build this pile would also have to be a huge – at least 55 feet tall with a jib of about 90 feet.

Let’s approach the problem properly by starting with the volume of rock to be excavated. For this we need the second important number: swell factor.

Swell factor is the increase in volume that occurs when you break up solid material into smaller, irregular pieces. For dolomite, the factors that I’ve found vary between 50 and 67 percent, with a median of 66. We’ll use the median, which means that every 100 cubic feet of solid dolomite excavated yields 166 cubic feet of broken stone that must be piled up somewhere.

We don’t know the width of the cut yet, so for now I’ll assume a base width of 28 feet plus a 6-foot recess in one wall for the towpath. The maximum depth – which we do know – was 31.5 feet.

The cranes were placed between 60 and 70 feet apart along both sides of the canal. This means, on average, each crane handled a 32.5-foot-long section (the average distance of 65 feet divided by 2). Taking the swell factor into account, this means 50,766 cubic feet of broken stone would be lifted out of the cut by each crane.

This results in a more reasonable-looking pile. The cone would be about 29 feet high and 82 feet in diameter. This represents the maximum pile size at the deepest part of the cut. Elsewhere, the piles would be relatively smaller.

Of course, the rubble pile would not be a cone. The crane would distribute the rubble in an arc described by the tip of the jib. This would reduce the height and width somewhat, depending on the size of the arc and the length of the jib.

The math gets a little dicier now, but an equation can be plugged into Excel to test different volumes and slopes. Then functions can be used to generate the basic shape in Terragen.

After adding a few random displacements, the shape is covered with thousands of rocks. The result is shown at the top of this post. Many variations can be made and placed in the scene.

It may not be 50 feet tall, but it’s still an impressive pile of rocks.

The Deep Cut was the last section to be finished on the original Erie Canal. For nearly five years canal planners and engineers had watched with increasing frustration as an army of immigrant laborers gradually chipped and blasted its way through the solid rock of the Mountain Ridge.

Now known as the Niagara Escarpment, the ridge is composed largely of Lockport dolomite and extends across western New York. It forms the ledge that Niagara Falls tumbles over 20 miles to the west. And in the 1820s it stood squarely in the canal’s path.

There was no alternative: The canal had to go straight through the ridge to reach Tonawanda Creek to the south, and then on to Buffalo and Lake Erie. To maintain a water level equal to Erie meant digging more than thirty feet deep in places. Through solid rock. With hand tools and primitive blasting powder.

“Through that ridge,” wrote the state’s canal commissioners in their annual report for 1822, “occurs the most extensive deep cutting, which we have any where to encounter. It is, in truth, very formidable, and exceeds seven miles in length.”

The excavation of the Deep Cut will make an excellent subject for a digital scene. To a large extent it will be inspired by George Catlin’s well-known lithograph, Process of Excavation, Lockport, which may be the only contemporary depiction of the effort.

Catlin, who would later become famous for his portraits of Native Americans, was commissioned to execute a series of scenes to commemorate the canal’s completion. His sketches were among the first lithographs printed in the United States when they appeared in Cadwallader Colden’s Memoir in 1825.

As art, Process of Excavation is undeniably dramatic. Lowering clouds and towering piles of rubble frame a deep vertical cut in which masses of men break and haul stone. Explosions roar in the distance. Overhead, spindly horse-powered cranes haul out the rubble to raise in piles fifty feet above the canal’s banks, according to the accompanying text in the Memoir.

The image has a certain Dante-esque feeling to it, of men laboring ceaselessly in the first circle of Hell.

As a historical reference, however, the lithograph raises a few questions. The rock piles seem too steep and too high, the canal cut too wide. There is little detail in the cranes. In fact, there is remarkably little detail anywhere. The indistinct mass of laborers in the bottom of the cut blends right into the rock walls.

Our goal will be to build a scene that is historically accurate and physically realistic. And despite the questions that remain, there’s no harm in starting on some of the details.