Whenever one surveys the industrial might of this nation—its buildings, factories, railroads, automobiles and trucks, pipelines, its Army and Navy and their equipment—the important role that iron and steel play in our very way of life is ever apparent. The iron or steel products that naval personnel come in contact with in their day-to-day life would include practically everything from paper clips and typewriters to 45,000-ton aircraft carriers. And, in manufacturing all this iron and steel, approximately 85% of the iron ore that was fed into the blast furnaces was at one time floated down the Great Lakes in ships of the renowned Great Lakes bulk freighter fleet.
The inland waterway formed by the Great Lakes is one of the most fortunately located transportation links known. At the extreme western end of the lake chain, in the Lake Superior region, lie the major iron ore deposits that have since the late 1800’s, supplied the United States with the largest percentage of its iron requirements. At the northern end of Lakes Michigan and Huron are vast beds of limestone—the material used as the fluxing agent in the smelting of iron. Then, coupled with the propinquity of the great coal fields of Pennsylvania, West Virginia, Illinois, and other states, we have the elements that—in combination with the cheap water transportation—have brought about the development of the greatest industrial area that the world has ever known.
The states that border the Great Lakes, with only 3/4 of 1% of the land area of the world and only 2% of its population, do the stupendous job of producing over 35% of the world’s steel. During World War II, the United States produced as much steel as all our allies and all our enemies combined, and most of it came from the Great Lakes area. The value of the products of the steel mills in this area is huge—some $6 billion per year, but the value of all the manufacturing in this same area, most of which has grown up near the steel mills, is eight times that figure, or about $50 billion per year.
The first record of blast furnace operation in this county dates back to 1645, but the industry had a slow early growth. As late as 1850, just over 100 years ago, the record blast furnace production in America was only 21 tons a day, and by 1870 the modern furnaces were averaging about 50 tons per day. In the Civil War period, with the great need for the implements of war, annual pig iron production in this country was less than a million net tons (in 1863), and the steel output in that year was only 9,004 net tons. With today’s pig iron producing capacity, 1863’s output would require just five days, and the steel produced in 1863 could now be turned out in less than one hour.
Shortly after the Civil War, with added discoveries of iron ore in the Lake Superior region and the development of the Bessemer converter and open hearth steel-making furnaces, the steel industry of this nation grew, doubling in production every two to five years until the turn of the century. From 1863 to 1900 it multiplied over 1,000 times, reaching a production of 11.5 million tons. By the beginning of World War I it reached over 26 million tons, and in the much heralded year of prosperity, 1929. steel output was just over 63 million tons.
The steel industry of the United States started the current year, 1954, with an annual rated steel making capacity of 124,330,-410 net tons. This represents an increase of 32 million tons, or 35%, in the eight post World War II years and a gain of over 52% since 1940. Blast furnace capacity as of January 1, 1954, was rated at 82,001,390 net tons of pig iron annually, an increase of 47% over 1940.
How the steel industry manifests itself in the Great Lakes shipping picture is indicated when the following facts are considered:
In the blast furnace operation that transforms iron ore into pig iron, the components introduced to make one ton of pig iron are approximately as follows:
Iron Ore 1.9 Tons
Limestone 0.4 Tons
Coke 0.9 Tons
Air Blast 3.5 Tons
6.7 Tons
To the resulting pig iron, the following principal materials are added to produce one ton of steel by the basic open hearth process:
Pig Iron .575 Tons
Steel Scrap .475 Tons
Iron Ore .050 Tons
Limestone .085 Tons
1.185 Tons
It is apparent that for every ton of iron and steel produced in the United States, more than a ton of iron ore has to be mined and shipped to the steel making centers. And thanks to Great Lakes shipping no blast furnace in this nation has been shut down in the past 75 years for want of iron ore, not even during that vital period in our country’s history from 1942 through 1945 when existing mine, transportation, and steel producing facilities had to be expanded many fold to meet the steel demands of a global conflict.
To meet American iron ore requirements in 1953—which was a record year in both steel production and iron ore shipments—a grand total of 119.2 million gross tons of ore was produced from United States mines and mills and 118.6 million tons shipped to consuming plants. These shipments had an estimated value of over $800 million.
Of the eighteen states that showed iron ore shipments during 1953, those in the Lake Superior district (Minnesota, Michigan, and Wisconsin) accounted for 80.6% of the total. Southeastern states (Alabama, Georgia, Tennessee, and Virginia) accounted for 6.4%, while Northeastern states (New Jersey, New York, and Pennsylvania) had an output in 1953 accounting for 5.0% of the national iron ore total. Western iron ore producing states (Arkansas, California, Missouri, Nevada, New Mexico, Texas, Utah, and Wyoming) produced 7.5% of the total ore output in 1953.
The great Lake Superior iron ore producing district is made up of three principal “ranges” (as they are called) in northern Minnesota, three in the northern Michigan-Wisconsin area, and two in Ontario just north of Lake Superior. In the life of these ranges, covering the period 1849 through 1953, total shipments from the Lake Superior region have reached the astonishing total of 2,922,983,000 gross tons.
The following table shows the total shipments of Lake Superior region iron ore in 1953 from each of these ranges and the proportion of the total output each range contributed in that year.
This iron ore is shipped from five major U. S. harbors—four on Lake Superior and one on Lake Michigan—and two Canadian ports. Ore from the various ranges moved over ore loading docks at these harbors during the 1953 season is indicated in the following table:
Range Vessel Shipments All-Rail* Total % of Total
U. S. Ranges
Mesabi 73,978,707 1,974,508 75,953,215 76.70
Vermilion 1,472,738 140,417 1,613,155 1.63
Cuyuna 3,676,469 38,215 3,714,684 3.75
Sou. Minn. 230,425 230,425 0.23
Gogebic 4,581,776 221,773 4,803,549 4.85
Marquette 5,391,062 180,440 5,571,502 5.62
Menominee 4,658,534 2,502 4,661,036 4.71
Total U.S. Ranges 93,759,286 2,788,280 96,547,566 97.49
Canadian Districts
Michipicoten 793,424 391,381 1,184,805 1.20
Steep Rock 1,300,874 503 1,301,377 1.31
Total Canadian Districts 2,094,298 391,884 2,486,182 2.51
Grand Total U.S. & Can. 95,853,584 3,180,164 99,033,748 100.00
* All-rail ore moves all rail from mine to final destination furnace.
(Figures per Lake Superior Iron Ore Association.)
Harbor Ranges Served 1953 Shipments Millions G.T. % of L.S. Total No. of Docks
Duluth-Superior Minn. - Wis. Cuyuna
Mesabi 58.0 63.5 7
Two Harbors Minn. Vermilion
Mesabi 21.1 22.0 3
Escanaba,
Mich. Gogebic
Marquette
Menominee 6.1 6.4 2
Marquette, Mich. Marquette 5.1 5.3 2
Ashland, Wis. Gogebic 3.3 3.5 2
Port Arthur, Ont. Steep Rock 1.3 1.4 1
Michipicoten, Ont. Michipicoten .8 .8 1
This ore is carried by lake vessels to the following principal unloading harbors on the lower lakes in approximately the following percentages:
Waterway Area Receipts
% Distance by Water from Duluth
Lake Michigan Chicago 27.0 808 miles
Detroit River Detroit 7.5 726
Lake Erie Toledo 3.5 781
Lake Erie Huron 2.5 805
Lake Erie Lorain 8.5 816
Lake Erie Cleveland 15.5 833
Lake Erie Ashtabula 10.5 876
Lake Erie Conneaut 12.5 890
Lake Erie Erie 4.5 917
Lake Erie Buffalo 8.0 986
The iron ore loading docks at the upper lake ports are highly specialized facilities designed for the exclusive purpose of ore shipments. They are long (from 900 to 2,300 feet), narrow (about sixty feet wide), finger type piers. On these piers are built steel and concrete structures reaching over eighty feet above the water level, supporting elevated pockets or storage bins. These pockets, spaced on 12-foot centers to conform with the 24-foot ore car length and the 12- or 24-foot hatch spacing on ships, hold from five to eight 50-ton railroad carloads of ore (200 to 400 gross tons) each. The largest of the docks is 2,304 feet long, has 192 pockets on each side, and a total storage capacity of 153,600 gross tons.
Railroad ore cars are shoved out along the four tracks on the top deck of the dock and the iron ore is dumped through the cars’ bottom doors into the dock pockets. From the pockets the ore is poured into the ships by means of long chutes that can be lowered into the freighter’s hatch openings. Thus, the transfer of iron ore from railroad car to ore vessel is entirely by gravity.
During the loading, the ship is shifted to various positions along the face of the dock to empty sufficient pockets to complete the load. This shifting is done with the ship’s mooring lines and winches.
Dock operations are closely synchronized with the movement of the ships and the arrival of ore from the mines. As a ship is being loaded, other railroad cars are being shoved up onto the dock to be dumped into the emptied pockets to make up the next cargo.
The docks are capable of loading a ship with a cargo of from 10,000 to 20,000 tons of ore in from two to five hours, and as many as six may be loaded simultaneously at the same dock. Some years ago, a special trial loading was conducted at one of the docks and at that time a steamer was loaded with 12,057 gross tons of iron ore in an elapsed time of 16½ minutes.
Unloading facilities at lower lake ports are capable of unloading a freighter in from six to ten hours.
* * *
The ships of the Great Lakes, their method of operation, the importance and economy of the traffic, all possess characteristics not obtaining elsewhere in the shipping world. The ships themselves are characteristic, for perhaps nowhere else are there so many design restrictions on large vessels. The overall length (which has now reached over 700 feet, but for the most part is around 600 feet) is dictated by the size of the drydocks that can dock the ship for repairs, and to some extent by the restrictions encountered in waterways leading to some of the unloading docks. The width of the ship (now grown to 72 feet) is governed by the ability of the loading docks to “throw” the ore to the outboard side of the ship. The depth (from 28 to 37 feet) has to be that which will give the most cargo capacity at existing draft limitations—25 feet being the controlling depth of the main channels. The depth of the hull is always the minimum necessary to permit designed draft in compliance with Load Line Regulations since ore is a deadweight cargo and large cubic capacity is not required. The ore usually occupies less than one-third of the hold volume.
Structurally, a lake vessel must meet many special requirements and much consideration is given to the strength of the ships in view of their abnormal length-to-depth and length-to-width ratios. The longitudinal strength is based upon a set of conditions quite different from those of a sea-going vessel. The maximum wave length encountered on the Great Lakes is about 350 feet and the average height 1/15 of the wave length. Ocean waves, on the other hand, may be 1,000 feet long, and the height is 1/20 of the length. In lengths of over 350 feet, therefore, strength requirements for lake vessels are considerably less than they would be for an ocean vessel of comparable size.
The shell of the lake freighter must be able to withstand damage from numerous dockings, for in normal operations a ship may make a landing at a dock, or a lock, nearly every day during the operating season. The internal structure, too, must be strong enough to withstand damage due to the many loadings and unloadings.
Fundamentally, the hull arrangement of lake vessels was established many years ago as being the most functional for the purpose of loading and unloading. The ships are arranged with their cargo hold in a continuous unbroken length amidships, with machinery aft. The pilot house, accommodations for the deck officers and crew, and owner’s quarters are at the forward end in a forecastle and forward deckhouses. The engineroom officers and crew, commissary crew, galley, and dining rooms are located within the poop and after deckhouse.
The hold space is divided into two, three, or four parts by transverse, non-watertight, screen bulkheads. The side tank bulkheads, which form the sides of the cargo hold, are sloped slightly inboard to make easier loading and unloading.
Most lake vessels make their return trips to the Head of the Lakes light and it is necessary, therefore, that the ships have ample ballast capacity in their wing and bottom tanks. The ballast capacity on the newer Great Lakes ships is equal to about two-thirds of the total deadweight. Prompt handling of ballast water is a requirement and the ships have a pumping capacity of up to 20,000 g.p.m.
The size, type, and spacing of the cargo hatches on the ore freighters is the result of the combined and simultaneous evolution of the loading and unloading equipment on the docks. The center to center spacing of the hatches must be a multiple of twelve feet, since the spouts on the loading docks are so spaced. The newer ships are fitted with 18 or 19 hatches, 44 feet wide (athwartships) and eleven feet long (fore and aft), spaced 24 feet center to center. This allows deck space between the hatches for stowage of covers during loading and unloading. Some of the older ore carriers have as many as 36 hatches, spaced on 12-foot centers.
Hatch covers in use on the Great Lakes ships include wooden leaves handled manually, or telescoping leaf-type steel hatchcovers opened and closed by cable and winch—both of which are secured with battens and clamps and covered with canvas tarpaulins in foul weather. The new ships have one-piece steel hatch covers, secured by special quickacting hatch clamps spaced two feet apart, and handled with a special gantry crane which travels the length of the deck.
* * *
The ships that are sailing the Great Lakes in the ore trade today are, for the most part, old ships. In the 1953 navigation season there were 286 ore carriers in the trade and over two-thirds of them—carrying over one-half the annual movement of iron ore—were more than forty years old. Forty-eight of these older ships were over fifty years old, and 112 were in the age bracket from forty-five to fifty.
Since they operate in fresh water, corrosion is not a problem. Frames and shell plates can be replaced from time to time, hatches, houses, boilers, tank tops, side tanks, etc., may be renewed, but the older ships are usually in excellent physical condition as far as hull structure is concerned. Depending upon the upkeep, the expected useful life of an ore carrier on the Great Lakes could be anywhere from forty to sixty years. There were six vessels operating in the 1953 U. S. ore fleet that were already fifty-eight years old, and several of the ships now operating in other trades under Canadian flag are well over sixty years old and still performing steady service.
The size of the ore freighters has increased steadily over the years, but since 1916 the 600-footer has been more or less the standard. The typical 600-footer has a keel length of 580 feet, a 60 foot beam, 32 foot depth, and 22 foot load draft. It has an 18,600 long ton fresh-water displacement and a 13,500 ton cargo capacity. The twenty post-war additions to the fleet have been vessels of up to 714 feet in over-all length, but most of them are 647 feet long, with a 70 foot beam 36 foot depth, a displacement tonnage of about 26,500 tons and an 18,000 to 20,000 ton carrying capacity.
There has been little advance until recently in the power plant installations on Great Lakes ore freighters—typically a reciprocating triple expansion steam engine of from 1,000 to 2,200 h.p. fed with steam from hand-fired, coal-burning Scotch-type boilers, and driving a single screw. Recently a few of the ships have been repowered by various types of plants including unaflow reciprocating, turbine, and Diesel, all of which are operating with varying degrees of success.
The power of those ships, however, has not gone above 5,500 h.p. and in most cases has been 4,000 h.p. The ships built since 1950 are almost all powered by 7,000 h.p. cross-compound steam turbines.
The speed of the ore freighters is from nine to about sixteen miles per hour (statute miles used almost exclusively on the Lakes for speed and distance computation). The ships make from 32 to 45 trips during the eight-month long shipping season, which usually runs from April to December. A round trip of 1,600 to 1,800 miles takes anywhere from five to eight days. In the 1953 shipping season one of the new freighters carried a total of 866,845 gross tons of iron ore in 45 trips to set a new record for a single season’s performance for a ship in the ore trade.
* * *
In addition to the ore freighters, there are numerous other ships operating on the Great Lakes that bring the total number of vessels to some 750. About 65% of these are of U. S. registry, and 35% are of Canadian registry. The various types include the bulk carriers for iron ore, coal, and grain; self-unloaders for carrying stone, coal, and cement; special carriers of automobiles, pulpwood, newsprint, pig iron, steel scrap, and sulphur; tankers, carferries, package freighters, and passenger steamers. In the four major commodities alone—iron ore, limestone, coal, and grain—200,000,000 net tons were carried on the Lakes in the 1953 shipping season.
Navigation on the Great Lakes, therefore, in addition to the large percentage of time the ships spend in restricted waters, is further complicated by the large number of vessels in operation which creates traffic problems not common on the ocean.
Pilots are not used on the Great Lakes, and tugs are taken only occasionally. Lake vessel skippers are famous for their unusual ability to wind their big ships around sharp river bends and through restricted channels, and to ease in and out of the narrowest dock-waters under all kinds of wind and current conditions without tugs or with a minimum of assistance.
Studies made a few years ago indicated that under normal conditions of trade vessels on the Great Lakes, were, on the average, less than four miles apart. This is borne out when it is considered that a total of 26,122 vessel passages were recorded at the Soo locks (between Lakes Superior and Huron) in the 270 days of the 1953 navigation season. This averages out to be 97 ships locking through every day, or one every 15 minutes, day and night, throughout the season. This accounts for only that portion of the lake vessel traffic that goes through to Lake Superior. The number of ships passing Detroit, at the hub of the Great Lakes, is even greater.
Separation of steamer courses on the open lakes was initiated as far back as 1911 and cooperation has been secured from all operators in the observance of these lanes. The Government has plotted them on all Great Lakes navigation charts. These provide separate lanes from eight to thirty miles apart for upbound and downbound vessels—a safety factor which has reduced the danger of collision to the minimum.
Rules of the road, enacted in identical form by the Governments of the U. S. and Canada for navigation on the Great Lakes, have been in effect for over fifty years and collisions due to confusion of navigation rules are of infrequent occurrence.
In the connecting channels and other areas where separate lanes are not practical, these big ships—about as long as a South Dakota class battleship, displacing the equivalent of an Essex class aircraft carrier, and developing about the same horsepower as a Bird class minesweeper—operate in close proximity to each other, under a wide variety of climatic conditions, with but rarely occurring mishap.
* * *
Referring to the figure mentioned earlier of 2.9 billion tons for the total ore production from the Lake Superior region to date—an equally astonishing fact comes to light when it is considered that over a billion tons, or about one-third of the total, has been produced in the relatively short 13-year period that has elapsed during and since World War II. This pin points the tremendous growth in the use of steel—but it also poses the question—how long can currently producing sources of iron ore keep up with the continued expansion of ore requirements, or even maintain normal production?
The reserves of iron ore in the Lake Superior region have been estimated in various quantities by numerous private and public authorities. It can easily be seen, when the total production figure above is considered, that a large quantity of the high grade direct shipping ore that lay close to the surface on the great Mesabi iron range has already been mined and shipped. However, this rich trough is only a fractional part of the huge iron formation that extends for almost a hundred miles across northern Minnesota and is from a quarter to four-miles wide and from 200 to 700 feet thick. Increasing use of ore washing heavy-media separation, jigging, and other beneficiating processes keep bringing new sources of iron ore, formerly too low grade to be marketed, into the production picture. Also, modern mining practices employing improved equipment such as huge drag-line excavators, long conveyor belts, and wear resistant alloy steels in mining tools, are constantly making economic operations out of ore bodies that formerly were considered unminable.
There is a great abundance of “taconite,” an iron bearing rock containing about 30% iron, in the Lake Superior region. The reserves of this material in northern Minnesota alone, are estimated to run into many billions of tons. At the present time there is considerable work being done to find an economic means to crush and grind this material to a point fine enough to make a magnetic separation of the iron from the gangue, and then agglomerate the resulting iron rich product into a form suitable for shipment and blast furnace use. Two major sized plants are now under construction in northern Minnesota, involving the expenditure of several hundreds of million dollars, for the commercial production of taconite concentrates. Several other plants, both in Minnesota and northern Michigan, are in the planning or early development stage and will also come into production in the next few years.
Thus, it must be conceded that iron ore reserves can not be measured by so many million tons of ore in the ground at any one time, but must be considered and gaged in the light of day to day technological progress.
Extensive ore deposits are under development by major U. S. steel companies outside of this country. These include high grade direct shipping ore sources in Canada, Labrador, Venezuela, Liberia, and other countries—some, or all, of the ore from which will find its way to the blast furnaces of this country. The tonnages of ore that will come from these foreign sources will become an increasingly important factor in the steel industry’s plans for future expansion or continued high level rate of output.
It is generally accepted, however, that this nation can and will rely on the Lake Superior region for a major portion of its iron require ments for many years to come.
Assistant editor of Skillings’ Mining Review, Duluth, Minnesota, a weekly magazine devoted to the iron ore mining and shipping industry, Mr. Harkins was on active duty in the Naval Reserve in both World War II and the Korean conflict. He also conducts a marine photography business.
★
BANTAM SIZE COMPASS
Contributed by COMMANDER GEORGE V. ROGERS, U. S. Navy
A newly commissioned Ensign aboard a destroyer in the Atlantic was being allowed to conn the vessel for the first time. After successfully completing several maneuvers, he started bringing the vessel to a new station by a succession of small course changes.
“Steady on course 355°T!” The helmsman brought her to the new course.
“Come right to course 365°T.” The helmsman, an old hand, immediately spoke up, “But, Sir, this compass only has 360 degrees.”
Whereupon the Ensign, with complete aplomb remarked, “Oh, damn these small compasses, anyhow!”
(The PROCEEDINGS will pay $5.00 for each anecdote submitted to, and printed in, the PROCEEDINGS.)
Iron Ore Traffic on the Great Lakes
By Wesley R. Harkins