diff --git a/binaries/data/mods/public/simulation/data/technologies/hellenes/civbonus_athen_delian_league.json b/binaries/data/mods/public/simulation/data/technologies/hellenes/civbonus_athen_delian_league.json
new file mode 100644
index 0000000000..336ee1fcb8
--- /dev/null
+++ b/binaries/data/mods/public/simulation/data/technologies/hellenes/civbonus_athen_delian_league.json
@@ -0,0 +1,11 @@
+{
+	"genericName": "Delian League",
+	"specificName": {
+		"maur": "Delian League"
+	},
+	"autoResearch": true,
+	"description": "Shortly after the great naval victories at Salamis and Mycale, the Greek city-states instituted the so-called Delian League in 478 BC, whose purpose was to push the Persians out of the Aegean region. The allied states contributed ships and money, while the Athenians offered their entire navy.",
+	"requirements": {"civ": "athen"},
+	"modifications": [{"value": "Cost/BuildTime", "multiplier": 0.75}],
+	"affects": ["Warship"]
+}
\ No newline at end of file
diff --git a/binaries/data/mods/public/simulation/templates/units/athen_ship_bireme.xml b/binaries/data/mods/public/simulation/templates/units/athen_ship_bireme.xml
index f27186c29f..6377f04435 100644
--- a/binaries/data/mods/public/simulation/templates/units/athen_ship_bireme.xml
+++ b/binaries/data/mods/public/simulation/templates/units/athen_ship_bireme.xml
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Entity parent="template_unit_mechanical_ship_bireme">
-  <Cost>
-    <BuildTime>15</BuildTime>
-  </Cost>
   <Identity>
     <Civ>athen</Civ>
     <SpecificName>Pentēkónteros</SpecificName>
diff --git a/binaries/data/mods/public/simulation/templates/units/athen_ship_trireme.xml b/binaries/data/mods/public/simulation/templates/units/athen_ship_trireme.xml
index 8d30583047..c2b1bbc14c 100644
--- a/binaries/data/mods/public/simulation/templates/units/athen_ship_trireme.xml
+++ b/binaries/data/mods/public/simulation/templates/units/athen_ship_trireme.xml
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Entity parent="template_unit_mechanical_ship_trireme">
-  <Cost>
-    <BuildTime>22</BuildTime>
-  </Cost>
   <Identity>
     <Civ>athen</Civ>
     <SpecificName>Triḗrēs Athēnaïkós</SpecificName>