Gunpowder Mills


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A detailed history of the waterways within the Mills, written by Richard Thomas,  is available from the Royal Gunpowder Mills.  Click here for their website.

Lock State Date Length Length - Working Distance Width Fall Removed or bypassed
Edmonsey (Powder Mill) Lock Built 1806       2' 6'' c1975
Gunpowder Mills Lock (East) Built 1878 40' 0'' 35' 0'' 10' 3'' 6' 0'' Extant
Gunpowder Mills Lock (West) Built 1896 61' 0'' 53' 6'' 12' 4'' 6' 0'' Extant
Waltham Pound Lock Built 1576 70' 0''   22' 2'' 3' 6'' 1592
Lower Island Lock (Gunpowder Mills) Built c1888       3' 9'' c1975

It is worth noting that of the four locks within the Royal Gunpowder Mills, two still exist. 







RGPF, Waltham Abbey

One which has gone is Edmonsey Lock, (above), built in 1806 to overcome the 30" difference between the Millhead Stream and the Powdermill Stream which goes on to join the Lee Navigation just below Waltham Common Lock and which disappeared in the creation of the Lee Valley Flood Relief Scheme in the 1970’s. (On the map to the right it is shown as Powdermill Lock)





The other, Lower Island Lock, (right) now lies under the M25.  This lock allowed the powder mill boats connection between the Lower Island works and  the South Site of the Royal Gunpowder Mills, which opened in 1888 as extensive Guncotton, Nitro glycerine and Cordite works.

A Minute of 2.8.1889 "That the Clerk write to the Superintendent of the Royal Gunpowder reference to their intention to build a Lock leading into the Old River Lee below Rammey Marsh so that Barges can convey goods and materials from the Gunpowder Works to the new Factory at Quinton Hill, and point out that Plans of the Work ought to be submitted to this Board and call attention to the fact that Toll can be charges on goods, etc., carried on any part of the Lee."                   RGPF, Waltham Abbey

A reply from the Ordnance Factories Office, dated 24.8.1889 to the effect that "without admitting that the Conservators had any voice as regards Works on the Waters of the Royal Gunpowder Factory there was no objection to the Engineer seeing the plans of the lock of the Lock in course of construction below Rammey Marsh Weir, but they could not admit the claim to levy tollage on Barges which might hereafter pass from the Powder Mill Stream to Cobbins Brook" 

The two remaining chambers are both within the Factory area and can still be seen. 


The lock built during the 1878-1879 improvements to connect the upper and lower levels of the main northern site.

This lock can be viewed from the Wildlife tower (a former Hydraulic Accumulator) at the northern end of Queens Mead in the Gunpowder Mills.

The unusual appearance of the lock is due to the decontamination works of the early 1990's when up to 3 feet of earth was removed. The original water level can be seen marked by the white staining on the wing wall.  Note the paddles which operated using a worm gearing which prevented the fast drawing of paddles and the resultant turbulence in the chamber which could be dangerous to boats carrying sensitive cargoes.


 The other chamber was built in 1896 to enable a toll-free waterway between the North and South Sites.  Christine Richardson


 Boats could now travel entirely within the Factory, without using Lee Conservancy waters, which would attract a toll.  This lock can still be seen from the north-eastern corner of the main car park at the Mills. The paddles used the same worm drive gearing as the lock above.


The original course of the River Lea (the Old Barge River ) lay close to and sometimes even through parts of the Gunpowder Mills  for nearly a hundred years, until the new channel to the west was built in 1769.  This led to a request from Colonel Askwith that the Trust should repair the Weir at Newton's Pool. 

On the 6th February 1867, the following appeared in the Minutes. "Newton's Pool Weir: This is an ancient work which has always been repaired by the Trustees although they have no interest in its maintenance.  The liability arose when the Powder Mill Stream (actually the Barge River) formed the line of Navigation. They were abandoned on the opening of the New Waltham Cut the latter end of the last century. I fear there can be no doubt that the Weir is in a bad condition and that its reinstalment will cost a heavy sum; if possible it should be thrown upon the War Department who are alone interested in the Head of Water being maintained."  This was followed by several entries concerning the cost and who should pay for the work. In the end the Trustees agreed to carry out the repairs at their own expense but on 9th March "It was resolved that the Clerk write to Major  Scratchley informing him that the Trustees will be prepared to proceed with the repair of the structure in September next, but that it must be distinctly understood that the Powder Mills and machines adjoining thereto must not continue in operation during this time as the Trustees could not feel justified in allowing their men to run the risk to which they would otherwise be subjected."  (NA Rail 845/16)                                                             

Whilst on the subject of the Royal Gunpowder Mills, it is worth noting that relations between the Mills and the Conservancy Board were not always without a degree of acerbity, although perhaps a hint of one-upmanship can be detected in the last paragraph.

A letter from Lt. Col. F L Nathan, 22nd January, 1904 to the Clerk, Lee Conservancy.

“Sir with reference to your letter of 1st July last on the subject of Tolls charged on boats passing between the Royal Small Arms Factory, Enfield Lock and this Factory at Quinton Hill, not going through any lock, I have to acquaint you that the matter has been referred to the Secretary of State for War who is advised that the Act 57 and 58 Victoria, Cap.CCV, is applicable to the case and that a minimum toll of 3/- for this journey cannot be recognized.  I have accordingly received authority to pay toll for the journey in question under General Section 1, page 3 of the Act, and Table A, Part 1, Scale A, (page 8 of the Act) subject to the conditions set at Special Section (11) (page 7 of the Act).

“I annex a statement of the tolls charged and held in abeyance pending the consideration of your claim and have inserted thereon the tonnage for which toll is payable and the amount of the toll for each journey.  I forward also herewith a cheque for 11s 8d in settlement of the account.

“In the list of outstanding tolls received on the 5th instant from your Chief Collector at Enfield Lock the following permits were wrongly included (the tolls for the same having been fully paid):- Nos: 2982, 3176, and 4003; and the following were omitted:- Nos: 2166, 2249, 3476 and 3710.

“I am , Sir, Your Obedient Servant, (Sgd) F L Nathan, Superintendent, Royal Gunpowder Factory”

The 1577 Pound Lock

Mention must be made of the other lock at Waltham Abbey although its name has not come down to us.  It was built in 1577 on a cut made between the Corn Mill Stream and the Old Barge River. Detailed specifications have survived, from which we know that it was built and lined with timber and had mitre gates at each end, making it probably the first true mitre-gated pound lock in the country

 It was described by William Vallens in his 1590 work “The Tale of Two Swannes”. In this poem, two swans make a journey down the Lea and one of the sights they marvel at is:

But newly made, a waterwourke: the locke.

Through which the boates of Ware doe passe with Malt.

This locke containes two double doores of wood,

Within the same a Cesterne all of Plancke,

Which onely fils when boates come there to passe

By opening of these mightie dores with sleight,

And strange devise, but now decayed sore.

The lock was completely destroyed in June, 1592 and navigation returned to the Old Barge River course, which is just out of sight at the top right hand corner of this photograph.  The route of the channel  built between the Cornmill Stream (bottom right) and the Old Barge River 400 years ago can still clearly be seen.





Approximate site of the 1577 lock



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This site was last updated 03-Mar-2021