PASSAIC monitors (1862 - 1865)


Jason (ex-Sangamon) 5/1898


No Name Yard No Builder Laid down Launched Comm Fate
  Camanche   Donohue, Ryan & Secor, Jersey City // San Francisco N Yd 1862 14/11/1864 22/8/1865 sold 3/1899
  Catskill, 6/1869- Goliath, 8/1869- Catskill   Continental Iron Wks, New York // New York N Yd 1862 6/12/1862 24/2/1863 sold 12/1901
  Lehigh   Reaney, Son & Archbold, Chester 1862 17/1/1863 15/4/1863 TS 12/1875-1879, sold 11/1900
  Montauk   Continental Iron Wks, New York 1862 9/10/1862 14/12/1862 sold 4/1904
  Nahant, 6/1869- Atlas, 8/1869- Nahant   Harrison Loring, Boston 1862 7/10/1862 29/12/1862 sold 4/1904
  Nantucket, 6/1869- Medusa, 8/1869- Nantucket   Atlantic Iron Wks, Boston 1862 6/12/1862 26/2/1863 sold 11/1900
  Passaic   Continental Iron Wks, New York 1862 30/8/1862 25/11/1862 auxiliary 1878, monitor 5/1898, sold 10/1899
  Patapsco   Harlan & Hollingsworth, Wilmington 1862 27/9/1862 2/1/1863 sunk 15/1/1865
  Sangamon, 6/1869- Jason   Reaney, Son & Archbold, Chester 6/1862 27/10/1862 9/2/1863 sold 1905
  Weehawken   Secor, Jersey City 17/6/1862 5/11/1862 18/1/1863 foundered 6/12/1863

Technical data

Displacement normal, t


Displacement full, t 
Length, m


Breadth, m


Draught, m

3.20 mean

No of shafts



1 Ericsson VL, 2 Martin boilers

Power, h. p.


Max speed, kts


Fuel, t

coal 150

Endurance, nm(kts) 
Armour, mm

iron; side: 127 - 76, turret: 279, deck: 25


1 x (1 - 381/11 short Dahlgren SB + 1 - 279/15 Dahlgren SB)

Lehigh, Patapsco: 1 x (1 - 381/11 short Dahlgren SB + 1 - 203/18 150pdr Parrott RML)

Camanche: 1 x 2 - 381/11 short Dahlgren SB



Standard scale images

<i>Camanche </i>1898
Camanche 1898


<i>Jason</i> (ex-<i>Sangamon</i>) 5/1898
Jason (ex-Sangamon) 5/1898
<i>Camanche </i>
<i>Nahant</i> in New York 1898
Nahant in New York 1898
<i>Catskill </i>1898
Catskill 1898

Ship project history

The Passaic class were enlarged and improved Monitors. There was a less pronounced overhang than Monitor, and the shape of the lower hull and its junction with the 'raft' were improved. Ventilation was better, and an 5.5m high funnel was fitted, protected by 8x25mm armour to a height of 1.8m. The pilot house was located on top of the turret but did not rotate with it, and had 8 x 25mm sides and a 2 x 25mm roof.  The 381mm gun muzzle did not project from the turret which was 6.4m internal diameter, and a smoke box was fined to keep smoke and fumes out. As a result the 381mm gunners could not see the target and had to aim via the 279mm or 203mm. The pendulum port-stoppers were replaced by crank-shaped forgings needing a 90° turn. Extra protection was added to some of the class as a result of experience at Charleston. Rings were fitted round the bases of turrets and pilot houses, the roofs of the latter were increased to 3 x 25mm and an extra 50 tons of 25mm deck plating added over magazines and machinery spaces.

Comanche was built in Jersey City, taken to pieces and sent to California on board Aquila which sank at San Francisco 14/11/1863. The sections were salvaged and reassembled, and Camanche launched as given above.

Ship protection

As in Monitor all the armour was built up from 25mm plates (deck 13mm) and the side was reduced to 102-76mm below water.


late 1863, Passaic: - 1 - 279/15; + 1 - 203/18 150pdr Parrott MLR

1864, all survived: armour of pilot roof was increased to 76mm, 25mm armour was added to the deck over magazines and machinery; + 2 x 1 - 76/11 12pdr SB field howitzers

by 1865, Catskill, Montauk, Nahant, Nantucket, Jason: - 1 - 279/15; + 1 - 381/11 short Dahlgren SB

by 1865, Lehigh, Passaic: - 1 - 203/18; + 1 - 381/11 short Dahlgren SB

Naval service

Weehawken foundered in a gale off Morris Island, Charleston 6/12/1863, from shipping too much water through open hatches and the hawse pipe before proper measures were taken, and it may be noted that Lehigh survived a Force 10 gale off Cape Hatteras when the water was more than 1.2m over her deck. These monitors were very vulnerable to mines and Patapsco sank 15/1/1865 in about 15 seconds after striking a mine with 27-30kg cannon powder charge which exploded 11m from the stem. Passaic served as receiving ship till 1878 and in 1895 she was loaned to Naval Militia. She was recommissioned for Spanish-American war but soon decommissioned and sold for scrap a year later.

) 5/1898