A Century of Service: The U.S. Navy on Cape Henlopen 


Early Naval  Communication Stations


This page describes the evolution of the various types of Navy communications stations that were on Cape Henlopen:


-A Coast Signal Service station in 1898.


-A Naval Wireless Station by 1904.


-A Naval Radio Station by 1912.


-A Naval Radio Compass Station

by 1918 until WWII.
















As the Navy prepared for the Spanish-American War, an Auxiliary Naval Force or "Mosquito Flotilla" was formed from the various state naval militias in order to defend the nation's ports and harbors from enemy attack.

To support that force by alerting it to the approach and location of the enemy, a Coast Signal Service, also manned by state naval militia personnel, was formed.  One of the 29 primary stations of that service was at Cape Henlopen.  The station occupied the former Philadelphia Maritime Exchange building adjacent to the Cape Henlopen lighthouse. 

It could receive reports by signal flags or flashing lights from passing ships that may have seen an approaching enemy force and send those reports via a telegraph line to Lewes for relay to the Naval Base at Philadelphia. 

By 1899, however, the Navy had begun evaluating and testing Guglielmo Marconi's new system of wireless telegraphy.  By Spring 1903, five shore stations and eight ships were equipped with a variety of wireless systems and additional shipboard installations and shore stations had been proposed. By 1904, some thirty coastal stations had been approved, extending along the Gulf and East Coasts and including one on Cape Henlopen. 

The government already occupied land on the Cape for a Lighthouse and Quarantine Hospital. The Navy established a wireless station on land nearer the point of the cape. The station was completed in 1906.

1910 chart showing location of the Naval Wireless Station relative to the Cape Henlopen Lighthouse and the National Quarantine Station.

Naval Wireless Telegraph Station, Cape Henlopen in 1906.


The station covered about 3 acres. It consisted of a main building for quarters and administrative spaces, a power building and storage building. There was a transmitting antenna (all in the foreground) and a receiving antenna near the small operations building. (in the background). 

The vertical transmission antenna (above) was built like a mast of a sailing ship, constructed of several long wooden poles lashed together by steel wire ropes and held upright by a number of guy wires.  It was 150 feet in height.

This mast height would theoretically give a maximum range of 137 miles.  Initial ranges were more like 30-50 miles, increasing with technology, training and experience to about 100 miles by 1909.  
The horizontal receiving antenna consisted of two poles about 150 feet apart with multiple wires strung between them for receiving on different frequencies.
Upon establishment, the station was equipped with a transmitter and receiver from the Massie Telephone and Telegraph company.  In the wiring diagram (below) the receiver  components are to the left, the transmitter components to the right. 
The interior of the station would have resembled the Naval Radio Station, Point Loma, California (below) which was a Massie-equipped station established at about the same time.

Interior of the Naval Wireless Station Point Loma, California showing the transmitter area. (Referring to the wiring diagram.) 

The "oscillaphone" detector and a "pump handle" telegrapher's key are on the wall to the extreme right.  The "pump handle" key was intended to reduce "telegraphers' paralysis" or what is 

known as carpal tunnel syndrome today.

The glass plate “condensers” are in the tall rack.  The “transformer” coil is on the wall and the “spark gap” surrounded by the “inductance” is on top of the chest. 

The coherer was the key component of a receiver, developed to respond to incoming radio waves. Massie, patented his own improved version (as illustrated on the wiring diagram above) and coupled it with a bell alarm to warn the operator of the incoming wave and a decoherer to prepare the coherer for continuous reception.

The pictured Massie coherer is believed to be from the Naval Wireless Station, Cape Henlopen.
Coastal naval wireless stations such as Cape Henlopen received meteorological information from the Weather Bureau and provided weather reports and storm warnings to ships at sea and forwarded reports from ships at sea to the bureau.  Information concerning wrecks, derelicts, ice and other dangerous obstructions to navigation was received from ships and provided to the Hydrographic Office and reports were broadcast four times daily.

Cape Henlopen operated at three kilowatts in the medium frequency range on wave lengths 425, 490, 625 meters or frequencies of 705, 611, 479 kilocycles respectively, with call sign PX.  In 1910 the wave length was 600 meters or 499 kilocycles and call sign was NAJ.

Between 1 July 1906 and 1 July 1907, its first year of operation, the Cape Henlopen Wireless station sent 39 messages totaling 594 words and received 115 messages totaling 2121 words.  It was the least active station on the East Coast. From July 1907 to 1908 the station sent 277 messages of 3700 words and received 291 messages of 5150 words. It was one of the moderately active stations along the coast.

In 1909, the Massie system was replaced by a "composite" system.  The receiver was almost certainly a Wireless Specalty Apparatus Co. IP-76 crystal detector (shown). These were considered the Navy standard between 1909 and 1914.  The transmitter may have been one of the more than 50 National Electric Signal Co. transmitters which made up 75% of the transmitters purchased by the Navy during this period. 
Equipment at the Naval Radio Station Lewes, Delaware in 1916.
In 1912, the Navy established the Naval Radio Service.  The Cape Henlopen Station was re-designated as Naval Radio Station Lewes, Delaware subordinate to the Fourth Naval District.  Initially the station was provided with equipment from a district patrol craft until standard Navy shore station equipment became available.


In preparation for WW I, the Navy was directed to take responsibility for all U.S. government radio communications and take over all government and commercial radio stations required. All others were to be closed.  Amateurs were directed to cease operations and dismantle their equipment.


Accordingly the Fourth Naval District took over a commercial transmission station atop the Wanamaker Building in Philadelphia and a Marconi-owned transmit and receive station at Cape May  (shown) for command and control of Fourth Naval District forces.

To enforce the restrictions on amateur radio transmissions and to detect possible transmissions from enemy agents, special listening stations were established and provided with newly-developed direction- finding (DF) antennae (shown).  Two stations were established in Philadelphia for the purpose.

During the war, Naval Radio Station, Lewes was used to communicate with district patrol vessels and ships in the immediate Cape area and for controlling the movement and anchorage of all ships in the approaches to Delaware Bay and in the Breakwater Harbor. 


In addition, the station was responsible for maintaining continuous watches on the international calling frequencies of 500 and 1,000 kilocycles at fifteen to eighteen and forty-five to forty-eight minutes after the hour for the purpose of guarding for distress signal transmissions.  This was especially important as the German submarine campaign reached the coast of the U.S., sinking numerous ships approaching the Cape. 

Naval Radio Station, Lewes    Radioman First Class

radio room.                                Charles S. Horn, Jr. on watch.

During the war, the German submarine operations against shipping off the Cape had shown that every hour a ship lost by slowing due to poor visibility and every day ships were kept at sea because of their inability to enter fogbound harbors they were increasingly  vulnerable to attack.
Thus, in mid-1918, anticipating an increased flow of convoys returning from Europe, the Navy began the establishment of "Radio Compass Stations" equipped with DF antennas in groups of three around the approaches to the major east coast ports and the entrances to the Delaware and Chesapeake Bays.  One station of each group would operate as the master or controlling station with two “slave” stations. By coordinating simultaneous bearings taken by all three, the master station could provide a ship with its location, improving its navigation and expediting its  approach and entry into harbor.
The process of converting Naval Radio Station, Lewes into a Compass Station begun in December 1918.  A new building and antenna were built just north of the former radio station building.  The “slave” stations were established at the Cape May radio station and in a new building just south of the lifesaving station in Bethany Beach.

The radio direction-finding station or "Naval Radio Compass Station" in 1922. 

It was in conjunction with the establishment of this station that the Navy formally acquired a reservation on the cape. 


It was in conjunction with the establishment of this station that the Navy formally acquired a reservation on the cape. That reservation consisted of all the area on the cape north 

of a line starting on the bay side were the shore line turned north straight across to the ocean.  That line was at the parallel  N 380 37.30’.  In 1932 the Coast and Geodetic Survey placed a marker “Radio” to mark the location of the Naval Radio Station, then being closed.  It is at N 3847’ 24.892”, W 750 05’ 28.820”.  That marker is recorded as being 150 or 250 yards south of the station buildings.  It  is still there today.

The direction-finding antenna at the Naval Compass Station.
Despite the label, the postcard (below) shows the Naval Radio Compass Station, Lewes Delaware in the 1920s.

While these stations were not completed by the end of the war, they proved useful in following years.

To obtain its position, a ship called Radio Compass Station, Lewes on the radio using the call sign NSD. Lewes alerted the Cape May and Bethany stations by telephone or radio and acknowledged reception to the ship.  Upon being acknowledged, the ship sent a series of three long dashes and operators at the three stations obtained bearings on that signal. 


The DF antenna at Cape Henlopen did not rotate as it was positioned to look directly at the approaches to the Cape and could develop a more exact bearing by the strength of the signal across the antenna.  The DF operators at the Cape May and Bethany stations rotated their antennas by a wheel that controlled the antenna. (See picture.) When they received the strongest signal, the face of the antenna would be pointing at the ship and a compass ring at the base of the pole on which the wheel was mounted would indicate the true direction the antenna was pointing, thus giving the bearing of the ship from the station.  Cape May and Bethany  forwarded their cross bearings to Lewes for plotting.

These bearings were plotted on a large chart of Delaware Bay mounted on a board which was hinged to the wall near the operator's desk. (See picture) The board could be pulled down to form a plotting table.  It had a hole in it at the location of each station and a string was threaded through that hole.  On one end of the string on the chart side was a pin and on the underside was a weight.  A compass rose was printed on the chart around the hole for the location of each station.  The string was pulled through the hole until the weight stopped it and it was aligned on the board with the bearing of the ship reported from that station and the pin was stuck in the board.  The bearing from Cape Henlopen and the cross-bearings from Cape May and Bethany provided a triangulated fix on the position of the ship.


Given the sensitivity of the equipment to get a precise line of bearing and the crudeness of the plotting system, the strings would not usually cross at a point.  Rather, they would indicate a triangular area within which the ship would be located.

In 1932, the U.S. Coast and Geodetic Survey placed a marker "RADIO" some yards to the south of the station, fixing its location accurately as N 380 47’ 24.892”, W 750 05’ 28.820”.


Then, on 11 May 1933, the Navy ordered a number of installations closed on 1 July 1934. Among the announced closings were the Navy Radio Compass Stations at Lewes, Bethany Beach and Cape May. Nevertheless, the station continued to be manned at some level until, in WW II, it was taken over and used by the Harbor Entrance Control Post (HECP). (For HECP, go here____.)

Meanwhile, the building of the former Wireless Telegraphy Station continued to deteriorate until it was torn down with the establishment of Fort Miles.
No evidence of these facilities remain in Cape Henlopen State Park today.
Area of the former naval communications today.

Photo Credits


-Title picture: The official seal of the U.S. Navy in the late 1800s.

-Coast Signal Service station adjacent to Cape Henlopen Lighthouse. Coast Guard photo from 1891 with permission from  Jack Beach, Cape Henlopen Lighthouse and Delaware Breakwater.  

-1898 Coast Signal Station: From Century Magazine 1901.

 -Naval Wireless Station in 1906: From: Franklin Brittingham Collection 205-12-1257. Courtesy of the Lewes Historical Society and Hazel Brittingham.

-Wiring diagram for Massie equipment at Naval Wireless Station Cape Henlopen: From John Dilks, "Vintage Radio Column" QST magazine, December 2013.

-Naval Radio Station, Point Loma California: From www.virhistory.com/navy/comsta-prewar.htm.

-Massie coherer: From Dilks.

-Wireless Signal Apparatus Co. IP-76 detector: From www.stonevintageradio.com.

 -Radio equipment at Cape Henlopen in 1916: From the Horn Collection. Courtesy of James G. Horn. 

-Naval Radio Station Cape May: From Wireless Age, June 1917.

-Direction-finding antenna:  From National Institute of Science and Technology Photo Gallery.  

-Naval Section Base radio room and Radioman First Class: From Horn Collection. Courtesy of James G. Horn.

-Naval Compass Station in 1919: From Horn Collection. Courtesy of James G. Horn.
-Naval Compass Station antenna: From Horn Collection. Courtesy of James G. Horn.
- Interior of Naval Radio Compass Station: From John Dilks "Vintage Radio Column" QST magazine, September-October 2006. This is one of 18 pictures of Naval Radio Station Cape May discovered by “Jimmy” and posted by John Dilks.
-Naval Compass Station 1922: From Franklin Brittingham Collection Courtesy of Lewes Historical Society and Hazel Brittingham.
-Postcard of "wireless station". Author's copy.
-Old Naval Wireless Station: From Horn Collection. Courtesy of James G. Horn.

-Current view of Naval Communications Station area on Cape Henlopen: Author’s photo and annotation.

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