Portpool



'''The "Portpool" area of Chester is the reach of the River Dee downstream from the Roodee to the where "Finchett's Gutter" (the downstream end of Flookersbrook) empties into the Dee. It stretches inland as far as the Watertower at the northwest corner of the City Walls. The River Dee once washed almost against the City Walls between the Watergate and the Watertower, but silting has resulted in the movement of the river's bed away from the walls. Indeed, the Watertower, built between 1323 and 1325, once stood in the river itself, but some 400 years later, by the date of the Lavaux Map (1745) the river's course had shifted significantly. The Watertower is now some 150 meters from the River. The area is somewhat off the "beaten track" for tourists, but there are a number of historic features worth noting.'''

The Port of Chester
The natural and extensive anchorage which once existed on the site of the Roodee may well have influenced the Roman choice to build a fort here and it is possible that a flotilla of the "Classis Britannica" was stationed here.

Anglo-Saxon sources imply that naval forces were stationed here in the tenth and eleventh centuries. It has been suggested that during the Dark Ages the main harbour at Chester may have been above the present weir at The Groves. From Norman times an important anchorage developed to the south of Chester Castle and explains the location of the medieval Shipgate. As silting continued (and ships drew more draught) the harbour moved progressively downriver. The most upriver remains of docks, in Chester itself, can now be seen at New Crane Bank below the boardwalk installed in the 2000's. John McGahey's "View of Chester from a Balloon" shows the Old Port c.1855. The Old Port has been linked to the Groves by the Riverside Promenade Heritage Trail.

By the 1230s Chester was a prosperous trading centre with a market of regional importance, two fairs, and a port. Its economy continued to expand, stimulated by royal interest and its role as a supply centre for royal enterprises in Wales, which more than compensated for the resultant temporary interruptions to the Welsh trade. The port and its anchorages, which extended from Portpool at the edge of the liberty along the western shore of Wirral to Redbank in Thurstaston, were the focus of longshore trade with north Wales, involving not only fish, timber, bark, and coal, but also slate and millstones from as far afield as Ogwen (Caern.) and Anglesey.

Features of Interest
A good way to explore the Portpool area involves a walk along the riverbank path from the Roodee down towards Crane Bank and on towards "The Cop". The city end of the path can be picked-up near Chester Castle.

The Dee Railway Bridge


In late 1846, the Shrewsbury and Chester Railway, later to become part of the Great Western Railway, first carried traffic. From Saltney Junction, access was gained to Chester via the Chester & Holyhead Railway. This latter line was carried over the River Dee, in the same place where it crosses today, by three 98-foot spans of cast-iron girders resting on stone piers. Both the bridge and the line had been designed by the great railway engineer, Robert Stephenson. The design was not unlike that of the Tay Bridge, which collapsed some thirty years later. Robert Stephenson was the son of George, of Rocket fame, who was often called the ‘father’ of the railways. Although a span of some 80 m (250 ft) was called for, Stephenson’s bridge had just two stone piers because of concerns about the foundations in the river bed; these were linked by a construction of cast-iron girders on which oak joists were laid that supported the twin tracks.

One thing which immediately strikes the visitor is that the railway bridge is much lower than the Grosvenor Bridge just a short distance upstream. The Dee railway bridge dates from 1846, while the Grosvenor Bridge was completed in 1833. Nothing could tell more clearly of the decline of "tall ships" plying their way to Chester over that 13 year period. When the Grosvenor Bridge was built it was the longest existing single-span stone arch road bridge in the world – at 200 feet across and 60 feet high, a record it held for thirty years. It is still the longest single masonry arch in the UK and number 19 in the world. There may however be other reasons why the Grosvenor Bridge was built on such a spectacular a scale: perhaps an urge on the part of the Grosvenors to have an impressive bridge at the end of their driveway leading to the racecourse.

Disaster
The River Dee bridge first opened to local freight traffic on 4 November 1846, following its examination and approval by an inspector from the government’s Board of Trade. Additional details emerging from the newspapers and inquest revealed that painters working on the structure had observed large deflections of several inches in the girders shortly afterward this examination. However, neither Stephenson nor his staff seemed to have been informed of the discovery. Just before the bridge was opened to the public, a small fracture was detected near the joint between two girders. Stephenson deduced it was the result of a casting defect. Piles were placed to temporarily support the faulty girder and a new section was cast as a replacement.



On 24 May 1847, the driver of the 18:15 Chester-Ruabon train noticed something was amiss as his train, crossing the span of the bridge closest to Saltney, began to vibrate strongly. The train had left Chester Station and consisted of one first-class carriage, two second class carriages, and a luggage-van; but it is stated that there were not more than two dozen passengers.

The driver boldly opened his throttle to clear the bridge and no sooner had he reached the bank than the bridge collapsed into the Dee, carrying away his unfortunate fireman, who was dashed against the stonework of the bridge and killed. The death toll included a guard, two coachmen and a few passengers (sources vary). Sixteen people (sources again vary) were badly injured, which is surprising considering that the whole train, except the engine, fell into the swirling waters of the tidal River Dee.

Curiously, Stephenson himself had inspected the bridge for safety earlier on the very same day. He had noted that hot coals falling from passing trains could set the wooden parts of the bridge structure alight and had ordered that the bridge deck be covered with tons of track ballast to prevent the oak beams supporting the track from catching fire. Undoubtedly, this massive loading of the structure with crushed stone contributed to the disaster. The ballast was laid in the afternoon, an operation completed just before the ill-fated train left Chester station at 6.15 pm. Many locals saw the accident and rushed to the aid of survivors. A number of observers provided accident inspectors with eyewitness accounts.

The brave driver, whose name was Clayton, had just seen his fireman slain, but not only drove his train to Saltney to summon help, yet then recrossed the bridge on the other track to warn oncoming traffic. Stephenson's bridge design was condemned by the inspector of railways as being too weak and generally unsound. The Official Inquiry (one of the first formal inquiries into a structural failure) stated:




 * "The train passed safely over the first and centre openings or arches, and the engine appears to have reached the middle of the third opening, or within about 50 feet of the end of the bridge before the driver felt any sinking. When he did feel it, he states, that he instantly put on his full steam, and by the momentum succeeded in clearing the bridge with his engine, and dragging the tender up with him. The stoker who was upon the tender was thrown off upon the land, and killed. The carriages, with all the passengers, were precipitated into the river, a depth of 36 feet to the surface of the water, which, at the time of the accident, was about 10 feet deep in the middle. The tender, having got off the line, was dragged up, rubbing hard against the parapet wall at the end of the bridge, as is evident from the stone-work of the wall being much disturbed; and was left standing upright at about 50 feet from the water's edge, and three feet off the rails; the engine having broken away from it, and proceeded with the driver (the only individual that escaped) to the next station."

The Investigation
The coroner’s inquest of the River Dee bridge collapse, complete with jury, expert testimony and eyewitnesses, appears remarkably modern in its form and conduct. Evidence was collected, firsthand reports recorded and drawings from the ‘crime’ scene prepared. However, the absence of a clear or agreed upon charge (manslaughter, professional negligence, human error?) makes the subject and purpose of the proceedings uncertain and its verdict questionable by modern standards of evidence and proof.

The investigation was one of the first major inquiries conducted by the newly-formed Railway Inspectorate. The lead investigator was Captain Lintorn Simmons of the Royal Engineers, and his report suggested that repeated flexing of the girder weakened it substantially. He examined the broken parts of the main girder, and confirmed that it had broken in two places, with the first break occurring at the centre. He tested the remaining girders by driving a locomotive across them, and found that they deflected by several inches under the moving load. His conclusion was that the design was basically flawed, and that the wrought iron trusses fixed to the girders did not reinforce the girders at all. The same conclusion was reached by the jury at the inquest. Stephenson's design had depended on the wrought iron trusses to strengthen the final structures, but they were anchored on the cast iron girders themselves, and so deformed with any strain on the bridge.

The following article comparing the Dee Bridge Disaster and the Tay Bridge Disaster appeared in the "Wrexham and Denbighshire Advertiser and Cheshire Shropshire and North Wales Register" on the 17th January 1880:




 * '''THE DEE RAILWAY BRIDGE DISASTER: Since the breaking down of the girder bridge over the river Dee, at Chester, thirty-three years ago, no railway calamity has occurred in this country of so appalling a nature as that which took place at the bridge over the Tay, near Dundee, on the night of Sunday, the 28th of Decem- ber, 1879. In magnitude, indeed, as well as, at present, in the circumstances of mystery and gloom in which the recent disaster is enveloped, the fall of the Dee viaduct is not to be compared with that of the Scottish structure. We were present at the inquest on the former occasion, and can never forget the intense excitement of those present in the court, an excitement which communicated itself in an unwonted manner, not only to the legal gentlemen concerned in the conduct of the case, but to the coroner, the magistrates, and the witnesses into the bargain. On that occasion, Major-General Pasley, one of the bravest officers who ever illustrated the distinguished corps for which he did so much, a man who made a plaything of death, trembled, turned pale, and became almost speechless under examination; so sorely did he feel the responsibility of having, some few months before, reported favorably as to the construction of the bridge. But the span of the Dee Bridge was only 108 feet. The girders which crossed that river were each formed of cast iron, in three pieces, bolted together, and trussed by wrought iron tension rods. The design was provided, under the sanction of Mr Robert Stephenson, by an engineer who was unique in his power of dealing with figures, but whose want of geometric sense, which is nurtured and invigorated by an early acquaintance with Euclid, was in this case unhappily illustrated. It was our opinion at the time, and one which has been rather confirmed than weakened by the reflections of a third of a century, that these truss rods were so disposed as to weaken, rather than to strengthen, the girders. The resistance to their strain was in the same direction as the resistance of the breaking weight. It came out on the evidence, with singular clearness, that the additional weight of a few inches thick of gravel which had been spread on the platform of the bridge, on the morning of the accident, had brought the insistent load so near the sustaining power of the bridge, that the weight and jar of the first train that went over the loaded structure were fatal. In our railway bridges and other building we have been apt to give full and proper attention, especially since the Dee Bridge fracture, to the question of breaking load and its due margin. We are taking for graated - and no doubt in so doing are ouly rendering common justice to the designers and constructors of the bridge - that the idea of the breaking down of the girder under the sheer weight of the train, as an efficient cause, is one that may be at once dismisssd from the mind. The structure is spoken of as remarkable for lightness and airy grace. But we have every confidence that neither the Scottish engineer nor the inspecting officer of the Board of Trade wolld have allowed themselves to make so closo an approach to the margin of safety as far as breaking weight was concerned. The additional surface exposed by the train to the wind, which has been compared by a naval observer to the hoisting of a sail of a vessel, may have added just that degree of resistance which passed the margin of the holding-down power of the structure. In case of a fracture under the weight of the train, the girder may be expected to be found very nearly under its original site. In case of an overturning of the structure by the wind, a sensible movement to the leeward may be anticipated.'''

Nowadays, it is possible to cross the river at this point by a footbridge (this has steep steps at either end) and L. T. C. Rolt (d.1974 - writer of "Red for Danger: A History of Railway Accidents and Railway Safety" (1955)) first gained his interest in trains while 'spotting' them from the trembling wooden footbridge as they passed on the far more sturdy replacement of the original bridge. Rolt was born in Chester and there is a commemorative plaque for him on the bridge by the canal dry dock.

Gasworks
In the early 19th century, the Roodee Gas Company built a gas works on land to the west of the railway viaduct (first used in 1846), which amalgamated with the Chester Gas Light Company in 1856. Historical maps from this period also show the Electric Light Building on Crane Street, designed by I. Matthews Jones and built in 1896. This building has local historical importance – being associated with a pioneering municipal undertaking to provide electrification to local farms.

The Port

 * THE PORT OF CHESTER IN THE FIFTEENTH CENTURY;
 * PALATINATE CUSTOMS ORGANIZATION IN THE PORT OF CHESTER;
 * SOME ASPECTS OF THE TRADE AND SHIPPING OF THE RIVER DEE IN THE EIGHTEENTH CENTURY;

The Railway Bridge

 * Dee Bridge Collapse on Wikipedia;
 * A detailed discussion of the disaster;
 * A reprint of a paper on the disaster;
 * A first hand report on the disaster;
 * Peter R Lewis, Disaster on the Dee: Robert Stephenson's Nemesis of 1847, Tempus Publishing (2007) ISBN 978-0-7524-4266-2
 * A review of Peter Lewis' book - contains links to further information;
 * Dee Railway Bridge at "Heritage Locations";