Lines of Torres Vedras - Description

Description

The three lines of Torres Vedras had redoubts and forts strategically placed in the top of hills, controlling the roads to Lisbon and using the natural obstacles of the land. They did not comprise solid lines, instead they formed groupings of heavily defended areas that were self-supporting, with mobile troops based in fortified camps ready to counterattack when necessary.

The first line, with an extension of 46 km, binds Alhandra to the estuary of the Sizandro river. The second line, 13 km to the south, has 39 km and binds the Póvoa de Santa Iria to Ribamar. The third line consisted of a defensive perimeter with 3 km, from Paço de Arcos to the Tower of Junqueira, protecting a beach of embarcation (St. Julian's) about 27 km to the south of the second line, to be protected by British marines.

Initially using the Lisbon Militia units plus 5,000 to 7,000 hired peasants and later by conscription of all people within 40 miles, supervised by 18 engineering officers and around 150 NCOs and at a cost of just £100,000 the work was completed, just in time.

Within a year, by the time the French arrived 126 forts and redoubts were built, with ravelins, detached batteries, etc. Rivers were dammed, turning large areas into swamps, ravines were choked with abatis, miles of walls were built, some 16 ft high. Lateral roads were constructed to enable swift movement of supporting troops, houses and walls demolished to clear fields of fire, hills were scarped to make an unclimbable precipice, and everything was organised to have channels where cross fire from artillery would decimate an attacking force.

The three lines were furnished with 247 pieces of artillery and provided with around 30,000 men, mainly Portuguese militia and home guard ordenanças, plus 8,000 Spanish troops and 2,500 British marines and artillerymen. This left the Regular army, of around 58,000 (being 24,000 Portuguese and 34,000 British), able to manoeuvre behind the first line, to points of danger depending on where the invaders attacked the lines.

The majority of the defences were redoubts holding 200 to 300 troops and 3 to 6 cannon, normally 12 pounders which could fire canister shot or round shot. The redoubt was protected by a ditch, normally 16 ft wide and 12 ft deep, with parapets 8 to 14 ft thick fitted with fire steps and the redoubts were pallisaded.

A possible eastern approach down the Tagus was protected with anchored gun boats.

The fourth line was built south of the Tagus in the Almada highs to hinder an eventual invasion coming from south, with an extension of 8,000 yards (7.3 km): It had 17 redoubts and covered trenches, 86 pieces of artillery, defended by marines, and orderlies of Lisbon, for a total of 7,500 men.

Work continued on the redoubts and 152 were eventually completed.

Substantial portions of the lines still survive today, albeit heavily decayed due to locals re-using 100,000 tons of stones, although there has been some recent renovation work undertaken using EC funding.