Thursday, 5 May 2016

Narragansett Bay Defences in the Early Civil War

We have an oddly large amount of information about the armament of Fort Adams, the only defence of Narragansett Bay, because the Mayor of Newport wrote to the local Newport Mercury newspaper a letter detailing the exact state, and it was taken to Congress by the representatives of Rhode Island. The Mayor was arguing for fortification of the bay and the mounting of the 140 unmounted guns in store at the fort. (ref)

Mounted guns
Barbette: 5x 32 pdr, 16x 24 pdr
Casemate: 18x 32 pdr, 11x 24 pdr
Bastions: 9x 24 pdr flank howitzers
Other: 1x 8" mortar, 2x 12 pdr field howitzers and 2x 6 pdrs

Unmounted guns: 77x 32 pdrs, 15x 24 pdrs, 48x 24 pdr flank howitzers

The 92 unmounted 32 and 24 pdrs don't have carriages, but 48 old and broken down carriages are available for probably the flank howitzers.

These unmounted guns represent a very large chunk of the ca. 600 seacoast guns in inventories that weren't mounted. Between the fortification of Washington, the Act to arm Fort Adams and issuing of guns to other forts this reserve of guns was used or committed to use in early 1862.

Geography

Fort Adams is still there (see Google Earth) and sits on an interior spit of Rhode Island (the big island the whole state is named after) inside Narragansett Bay, defending the East Passage, one of the two channels into the bay - the deeper one that can easily admit ships-of-the-line with more the 50 feet of water in the channel. There are two other inlets of importance, the West Passage to the west of James Island with Dutch Island in it and the Sakonnet River to the east of Rhode Island. The West Passage is navigable to frigates at all tides, but only to ships-of-the-line at high tide. The Sakonnet is navigable for ships-of-the-line only upto Church Point, frigates upto Sapowet Point (with a tricky bit at Fogland Point) 2 miles south of the bridge joining the island to the mainland, but sloops and gunboats can steam literally right upto the bridge.

The geography makes the entire bay undefendable unless all three inlets are heavily defended. If the Sakonnet isn't blocked then a single enemy gunboat can steam up the river the drop the bridge (a simple wooden affair, the stone bridge was built in the 1890's) and cut the island of Rhode Island off from New Hampshire. The Western Passage means that (a) the fort can be bypassed and the cities of Providence etc. put under the gun without any intervention and (b) landings of James Island can be affected and the Fort reduced by a land battery. Historically in 1863-4 the state built an earthwork battery of 8 guns (7x 8" shell and 1x 32 pdr) on Dutch Island to defend the West Passage, but that's in the future.

Fort Adams

The fort is a pretty standard single tier fort of the period. The casemates prettymuch all point northwest and north to fire into the shipping channel, thus those 19 guns all play on any force coming through the channel.

Fort Adams Plan, showing that the casemates all point NW and N

The barbette had 21 guns in early 1862, but we don't know what arcs they were in. Probably the majority were on the bastions.

The field pieces were probably in the redoubt, an infantry defence to the south of the fort proper.

Redoubt of Fort Adams

Attacking Fort Adams

Any enemy (probably the RN) will have a surprisingly easy time in 1862. The fort can be isolated easily with a few shells at the bridge and one can land a few guns on James Island and reduce the fortification. Being on a spit any attacking squadron can run down the shipping channel and get behind Fort Adams in Brenton Cove, which is very lightly defended. Once there they can basically reduce the fort without danger.

Given the geographical problems the fort had, and the fact that it's pointless and doesn't defend Providence at all due to an alternate channel, despite being one of the strongest and best armed forts in the US in 1861 it would not hugely worry the RN.

Wednesday, 4 May 2016

Boston Harbor Defences in the Early Civil War: Draft

I was going to post about Boston's Harbor Defences in late 1861 but reading this it turns out I don't have to - not a single fort was armed. In April '61 was a single condemned old gun at the main fortification (Fort Warren) and about 20 small guns facing landward at Fort Winthrop (ref) and nothing had been done since..

Of course, in Spring 1862 the state government got concerned and were basically told by the Federal government to contract for their own guns, which they did. By late 1864 the armament was more substancial but that's then.

In spring 1862 the only thing stopping, in event of war, a British cruiser steaming into Boston and taking possession of the city is a bluff in the papers that the forts are armed, which will disappear about 30 minutes after said cruiser appears on its blockading station.

Sunday, 1 May 2016

New York Harbor Defences in the early Civil War (3): The Backdoor

The other approach to New York is via the East River. Now the Long Island Sound separates this approach by a long distance from the southern approach. Along that stretch of coastline are a series of harbours the RN intended to blockade. To enter the East River from Long Island Sound one has to pass a fort at Throg's Neck.

Fort Schuyler






Fort Schuyler was a two-tiered fort with the three smaller walls having 20 embrasures each and the northern wall 28. The back (longest side) was accommodations and had no casemates. Thus 88  casemated mounts for 32 pdrs were available in the curtain walls. The 3 caponiers (the sticking out bits) each have embrasures for 16 flank howitzers firing across the walls to shoot down any infantry attempting to escalade and a pair of heavier guns (32's) firing outwards. The barbette including the back apparently can be crammed with 90 guns, but (without a plan) roughly one gun above each casemate embrasure plus 1 on the caponier is reasonable.

In January '62 she had 96 guns of the 283 full establishment (listed here). All the small guns were meant for the back of the fort to stop an escalade.




Essentially any attackers not running past are only fighting the north wall with 28 casemated guns (a mix of 8" shell guns, 42 pdrs and 32 pdrs) and the barbette armament of 1x 10" shell gun (maybe a second) and roughly 14 other barbette guns of the same sort in the casemates. Probably some 42 guns - roughly equal to a single ship-of-the-line in firepower, assuming that is the 96 guns including filling the north wall (which is sensible).

The lack of sea room is more of a problem than the actual fort. It's relatively tight, which limits the size of the force that can be deployed. However, if one is not in a hurry then gunboats can actually stay out of range of the fort (effective range ca. 2,000 yds) and use rifled guns to smash it to pieces from the area E-NE of City Island. If an ironclad or two is available (such as Terror or Thunderbolt, not necessarily Warrior) then they can lay off a few hundred yards and shatter the walls in probably less than an hour.

New York Harbor Defences in the early Civil War (2): The Harbour Islands

Once the fortifications at the Narrows are neutralised any attacker can enter the bay. There they will be confronted by several fortified islands and Castle Clinton on Manhattan. Of course by 1862 those forts no longer protected the city with the enhanced range of weapons available, as per this report to Congess (ref). The same report also notes that the Navy Yard is essentially undefended landwards. That's true - a force of marines landing in Gravesend or Jamaica Bay are only five or seven miles from the yard (in 1776 Government forces landed at Gravesend Bay to liberate the city), and the US could need to station a large force in Brooklyn to defend the navy yards (a division) in addition to a force on Staten Island. Of course, in my last I completely neglected the fact that the Kills (the river system that separates Staten Island from the mainland and makes it an island) is navigable to gunboats.

Anyway, the inner layer of the defence consists of the following forts.


Fort Gibson (Ellis Island)

Easily covered as in 1861 the US had dismantled the fort to make a new powder magazine for the USN

Fort Wood (Bedloe's Island, now Liberty Island)

Fort Wood, a pre-war of 1812 star fort, still exists today as the foundations of the Statue of Liberty Enlightening the World (the full name of the statue).
Lady Liberty stands on Fort Wood



The old fort was designed to fire to the east and create a crossfire with the fortifications of Governor's Island and prevent any enemy from dashing through the Brooklyn Navy Yard, although of course this was pre-steam.

The walls were quite think, but not casemated. All the guns are on the barbette tier, and roughly a quarter would bear in each direction. In January 1862 there are 54 guns which means almost every heavy gun mounting point is full (56 potential mounts - see the Secy of War's 1860 report), a large increase on her 12x 32 pdrs of 1851. Thus say 19 guns can engage.



Fort Columbus and South Battery

Governors Island - the orientation is that the triangular battery at the top is the South Battery

Fort Columbus (renamed Fort Jay) and Castle Williams still exist, and can be seen on Google Earth here. South Battery has been demolished.

Fort Columbus has her firepower concentrated to the north of the island,a survey of her (page 247 here) reveal her armament bearing on different directions, assuming all mounts full, to be 12 x 32 pdr and 6x 24 pdr to the south, or 12-13 32 pdrs to the SW (as the 24 pdrs as masked).

She had 60 guns, a mix of 32 and 24 pdrs. There may have been a few old pattern 8" shell guns in the mix (her 1851 armament includes 5 of these).

South Battery is the work that faces out into the bay, and in January 1862 mounted 5 guns (probably the same 5 32 pdrs she mounted in 1851). It was an open barbette work with little protection for the guns or gunners.

Castle Williams
 Castle Williams as she now stands (wikipedia)

Castle Williams is a round tower with three tiers of casemates (only the first and second tiers armed, the third tier was converted to accommodations for the garrison and a barbette. Floorplans are available from the NPS The Castle is essentially fully armed with 70 guns (78 mounts) and her arcs go from south to northeast. The guns were a mix of 42 pdrs, 32 pdrs and 24 pdrs, but nothing definite on the makeup (in January '65 she mounted 26x 42 pdrs, 26x 32 pdrs and 5x 15" Rodman - the later replacing the entire barbette armament), however the data indicates the 26x 42 pdrs were on tier 1, the 26x 32 pdrs on tier 2 and the roof could probably only take 24 pdrs (which her 1851 return indicates), and needed strengthening to mount the 15", with that work occurring 1863-4.

The arcs are such that only 2 embrasures on each level could bear on any one target (hence 4 guns) and the circular nature makes concentration of fire impossible. Likely against an attacking squadron to the south or southwest she could bring 6-12 guns into action.

The walls were 8 ft thick at the base, and 6 ft on the upper levels.

Castle Clinton (Manhattan)

Is unarmed and abandoned as a fortification.






Attacking the Fortifications

Unless an attacker runs the islands they will be engaged by roughly 42-49 guns, mostly 32 pdrs with some 42's and 24's thrown in. Compared to the Narrows this is easy, hence one reason for writing them off as a serious defence.


Saturday, 30 April 2016

New York Harbor Defences in the early Civil War (1): The Narrows

New York Harbor was very vulnerable, as John G. Barnard pointed out in his Dangers and Defences of New York, and Morton pointed out in his Memoir on the Dangers and Defences of New York City.

The Harbor Defences of New York in 1861-5 really consisted of 3 tiers - firstly there were forts built to defend the Narrows and the entrance to the harbour. Secondly two of the islands in the harbour (Bedroe's and Governor's) were fortified as a second line to stop an attacker landing in New York City and the Brooklyn Navy Yard (although with rifled guns once past the Narrows these could be bombarded easily). Thirdly the "back door" of the East River defended by Fort Schuyler prevents that approach. There was no work on Sandy Hook at this point.

With the Trent crisis unfolding the Governor of New York inquires as to the state of defense of NY on 18th December, and Totten replies with a long letter on 30th December. As always with Totten you have to read between the lines - only the governor of Maine persisted with Totten and got the truth out of him as to the actual numbers of guns defending Maine. Totten's letter reveals that the forts are far short of their compliment of guns. Delafield in January 1862 actually reported the numbers of guns mounted after the crash rearming thus.

The real defence of New York Harbor is the forts at the narrows - the point between Staten Island (west) and Brooklyn (east) which controls the entrance to the harbour. Their armament in late 1862 is known, and taking that number, which includes some crash rearming during 1862, as a basis we have the following.

The Narrows Defences

The defences at the Narrows was based around stopping the enemy from running into the harbour, as we will see from the arcs and strength of the forts they had no real chance of avoiding being easily reduced by an enemy to their south.

Fort Hamilton

Fort Hamilton

Fort Hamilton is the only fortification on the Brooklyn side ("east bank") and is a rather weak single tier fort. She's still there but the casemates have had buildings built on them and I'm sure there wasn't a swimming pool in 1861-2. See google earth at these co-ordinates. She looks like this:

Fort Hamilton in 2006 (wikipedia)

Her walls are thin (about 3 feet of masonry). She mounted in late 1862:

Barbette - 18x 32 pdrs and 25x 24 pdrs
Casemate - 15x 32 pdrs
In the redoubt - 8x 24 pdrs and 1x 10" mortar

This is a rather big jump on the winter of '61-2, when in September '61 the fort was essentially unarmed and being prepared for 51 guns, and in January 1862 actually mounted 68 guns (one more than in December 1862), but the natures of guns are unknown (likely includes field guns). The casemate was a separate canonier to the NE of the fort proper that was to protect the landward approach  the guns don't fire out to sea (well the mortar could, but good luck hitting anything!). The guns almost all face roughly west, and if an enemy was to the south trying to reduce the fort she could probably only reply with about 3 guns on her casemate.

The redoubt was square, and 3 24 pdrs could engage towards the bay.

Fort Tompkins

This fort (on the Staten Island shore) was incomplete and is a non-factor. She still exists today here, and only really engages into the narrows. It was effectively an additional battery added to Fort Richmond (below) as this picture (from fortwiki) makes clear:

Forts Tompkins (top of hill) and Wadsworth (ex-Richmond).

Fort Richmond (now Fort Wadsworth), Battery Hudson and Battery Morton

Fort Richmond was the major fort on the Staten Island shore of the Narrows. Due to her geometry with a south facing wall she'd be the major opposition to any reduction of the Narrows forts. In late 1862 she has 60x 8" shell guns, in September 1861 is unarmed and in January '62 she has 46 guns. The arcs are unknown, but the three-tiered fort was only pierced for guns on her third tier (made clear from the image below), and 60 guns might be more than she could mount, counting casemates and gun circles, but assume 60. Roughly 20 guns each fire south, into the narrows, and north (to flank any ships running past the forts). Assumidly the north facing guns were mounted last.


Battery Hudson and Battery Morton were single tier barbette earthworks being built facing south on the slopes of the hill that Ft Tompkins was on. In late 1862 the armament is reported as 32 "old-fashioned" smoothbores, a single rifle and an as yet unmounted 15" Rodman gun for Hudson (Morton was demolished as being useless in 1862 and a new battery was complete in 1865 to replace it). From earlier reports the smoothbores are 32 pdrs. Thus in January 1862 the two batteries together mounted 40x 32 pdrs.

Fort Lafayette

Fort LaFayette, what became the "American Bastille" due to being used as a political prison, was built offshore on Hendrick's Reef near Fort Hamilton, and was destroyed to place the tower of the suspension bridge across the Narrows on.


Whilst her walls were quite strong a fatal flaw caused a massive fire in 1868 - in order to save weight the main structures aside from the walls were wooden, not stone or masonry. This also prevented the mounting of heavy guns en barbette due to the weight.

Her armament in January 1862 was 68 guns (mostly 32 pdrs, roughly 6 24 pdrs on the barbette) - essentially a complete complement, and roughly 20 guns fired across the Narrows, 20 to the NW and 20 to the south.


Attacking the Narrows Forts

Staten Island side can put roughly 60 guns into the fight - 40x 32 pdrs and 20x 8" shell guns, whilst the Brooklyn side adds about 20x 32 pdrs and about 6x 24 pdrs.  Only Bty Hudson has empty mounts (20) facing this way A naval squadron would be under fire from 86 guns, roughly the same as 2 small-medium size ships-of-the-line or 3 heavy frigates, with no huge calibre weapons. The options for attack are.

1. Bombardment

If a force of ships-of-the-line and other heavy ships is available a standoff bombardment is possible. However if the attackers bring gunboats then the heavy rifles will make short work of many of the works (RN gunboats were equipped with 1x 110 pdr Armstrong and 1x 40 pdr Armstrong).

If Warrior (historically scheduled to arrive in the Americas in late February '62 from the Tagus in company with HMS Edgar), Black Prince (March '62) or Defence (April '62) are available then the forts are completely untenable. Warrior could lay a few hundred yards off Fort LaFayette, Hamilton or Richmond and reduce them to rubble in a few hours for literally no damage.

The open barbettes of Ft Hamilton and the Btys on the Staten side are horribly vulnerable to mortars or shells from rifled guns.

2. Run the fortifications

Only really possible with armoured frigates.

3. Landing troops

The Staten side in particular would be very vulnerable a battalion of Marines landing, overrunning the batteries (which were not prepared for defence) and then getting behind Fort Richmond (see above for how open it is to the rear). Hence both sets of fortifications would need very significant US land forces to prevent them being overrun.

Conclusion

A determined attacker with a significant fleet of warships could easily reduce the fortifications in the Narrows. The defences have not yet adapted to the new reality of steamships, rifled guns and especially armour.

Thursday, 28 April 2016

Fort Delaware and the Defence of the Delaware River (and Brandywine Creek)

During the Civil War there were two forts* on the Delaware River - Fort Delaware on Pea Patch Island and further upriver (beyond the confluence of the Delaware and the Christina, which the Brandywine is a tributary of) was the ruined Fort Mifflin on Hog Island which "guarded" the Navy Yard. Only Fort Delaware was a significant defence, and once past that the Du Pont powder mills, the Philadelphia Navy Yard (a more minor facility - doesn't have one of the 5 remaining dry docks in Union hands for example) and the port of Philadelphia are wide open. The Delaware is navigable to "large ships" upto Philadelphia, and sloops upto Trenton, NJ (ref), although probably only at high tide - really the depth at low tide of the channel is 3.5 fathoms (21 ft), which is suitable for heavy frigates (51's) but would rule out ships of the line.

 Fort Delaware

Fort Delaware in 1861-2 mounted the following ordnance:

20 Flank Howitzers
8 8" Columbiad shell guns on the second tier
5 10" and 14 8" Columbiad shell guns on the barbettes
(ref)

The states in the OR show she still had the same 47 guns in December 1863.

Thus we should considered whether an armament of 27 guns (22 8" and 5 10") is sufficient to stop an enemy squadron. I'd like to know where the 27 naval guns were placed (the flank howitzers were placed in the 5 bastions to sweep across the front of the fort and repel infantry attack).

The plans show 5 bastions, and the bastions had larger gun circles, so our 5 10" guns are there, and typically only 2 (at some angles 3) of the 10" will bear on any attacker.





Plan of Fort Delawares Barbette Tier

But which arcs are the 22 8" in? In the plans above the right hand side is the one that faces approaching ships in the river. I suspect all the armament faced in that direction, which would mean if an attacker ran past the fort and engaged from the W or NE they would demolish the fort in short order. Fort Delaware is of about the same strength as Fort Pulaski, which proved just how vulnerable these forts were when a small Union force on another island bombarded it into submission.

Frankly, I don't see Fort Delaware stopping a significant attack for more than a day. If the Royal Navy were to roll a couple of heavy frigates up the river then it's essentially game over.

* Some point to Fort DuPont (commenced 1863) and Fort Mott (commenced 1872), but obviously these didn't exist in 1861-2.

Edit: The British Hydrographer's Report on the Delaware

Having check contemporary charts (well 1877, accompanying the proposal to dredge a 26 foot deep at low tide channel) the British (who of course had charts of the river) were spot on thus:

The DELAWARE is a large inlet of the sea, between the States of
Delaware and New Jersey, extending in a general north and south
direction 90 miles inland, having a breadth of 10 miles at its
entrance between Cape May in the north and Cape Henlopen in the south.
It is a rather shallow estuary, its depth varying from 15 fathoms at
the entrance to 10, 8, and 5 fathoms 20 miles up, and this depth it
maintains farther to Bombay Hook Road, which spot line-of-battle ships
might reach at all times of tide. Spring tides in the lower part of
the river rise six feet, and in the upper parts seven feet.

The main channel entrance is four miles wide, with ample depth of
water in approaching from the southward; vessels standing in from the
eastward must be on their guard against some outlying patches which
will require to be buoyed. The channel upwards is direct and of a fair
breadth, but having shoals on each side it will be necessary to place
buoys or small vessels on them. There is also an entrance channel
close to Cape May to the north, which leads into a deep-water bight,
but to cross from thence over the Round shoal into the main ship
channel vessels are limited to 20 feet draft. Immediately to the
westward of Cape Henlopen is an artificial harbour formed by a
detached breakwater, within which the largest vessels could lie at
anchor, but they would be within half a mile of the south shore, and
therefore exposed to any guns which might be brought down to the
beach, although from the nature of the coast it is not probable that
such would be attempted.

At Bombay Hook Road, at 40 miles from the entrance, the river banks
are still four miles apart. Thence they gradually narrow and a flat of
only three and a half fathoms at low water extends for 9 miles as far
as Reedy island point (but with a seven feet rise of tide), when the
river again deepens to six and seven fathoms, which it retains up to
abreast Delaware City at 53 miles from the entrance. Another four
fathom flat then occurs for five miles with a very awkward bend in the
river between shoals, then again deep water of six, seven, and eight
fathoms for three miles in which the largest ship might lie afloat
just below the entrance to the creek leading to Wilmington.

The river now narrows to one mile in width, and the navigation becomes
more intricate; the depths vary from three and a half to five and six
fathoms for 16 miles further, when a bar of 17 feet at low water, or
24 at high-water springs, at eight miles below the city of
Philadelphia, limits the navigation for large class ships. Up to this
bar, however, at 77 miles from the sea, a line-of-battle ship could be
navigated, at tide time, with a competent local pilot, and over the
greater part of the river might be anchored in ample depth to ride at
low water of spring tides. Once across the bar, water again deepens to
four, five, and six fathoms, and there is a depth of 9 fathoms
opposite the quays of Philadelphia, at a distance of 85 miles from the
sea. The river is further navigable at tide time for gunboats or
vessels of 10 feet draft as far as Trenton, the capital of the State
of New Jersey, 30 miles above Philadelphia.

The towns on the banks of this large inlet ar Delaware City,
Newcastle, Wilmington, and Philadelphia on the western bank, with
Trenton and the populous village of Salem on the East or Jersey shore.
Delaware City, notwithstanding its imposing name, does not appear to
have more than some hundred inhabitants, and to be of no importance.
Newcastle has an extensive factory for steam engines, and is the
terminus of the Frenchtown railway, population about 4,000.
Wilmington, well situated between the Christiana and Brandywine
creeks, is the chief town of Delaware county and has 22,000
inhabitants. The ground on which it stands rises 112 feet above the
river. It has numerous factories and flour-mills, and is specially
important as the site of the largest gunpowder mills in the Federal
States; the chief establishment is owned by a person of the name
Dupont. [The other large powder mills, as already mentioned, are a
short distance from Newhaven on the Connecticut river, and owned by
Hassard] Christiana creek is narrow but is navigable for gunboats and
steamers of 10 feet draft at low water, or of 17 feet draft at tide
time up to the town of Wilmington. The powder mills would seem to stand
about 2 miles to the north-east of the town, on the Brandywine creek,
and near the river Delaware, as Dupont's landing place is marked on
the chart.  

I of course express my gratitude to the late Dr. Angus McLellan for typing this up over a decade ago.

Essentially some ships of the line can get upto and over the bar at Hogs Island (where the derelict Fort Mifflin is) at high tide but not low tide, whilst heavy frigates can transit the river upto the bar at low tide, but must cross the bar at high tide. Ships of the line can pass the flats in front of Fort Delaware at high tide, and frigates at low tide.. Smaller vessels (gunboats and sloops) can transit the entire river unencumbered (even by the bar) even at low tide.

Brandywine Creek is navigable to gunboats at low tide  (and ironclads of the Thunderbolt class etc.), and to sloops at high tide.

The BBC documentary that got me booted from AH.com!

I've recently rewatched the BBC documentary "Racism: A History". It's fascinating to look back and remember that me referencing this extremely anti-racist, anti-slavery documentary got me expelled from AH.com!

Still worth a watch, and I still don't think the civil rights issue went away with emancipation, no matter what the AH.com right-wingers think.