Rails action being called multiple times per request - ruby-on-rails

Question

I have a controller action that's being called three times per browser request. Any ideas? config/routes.rb and application_controller.rb are totally straightforward.
Code below,
config/routes.rb
Rails.application.routes.draw do
root 'tiles#index'
+
controllers/tiles_controller.rb
class TilesController < ApplicationController
def index
puts "this line prints three times in the console per request"
end
+
tiles/index.html.erb
<% if notice %>
<p id="notice"><%= notice %></p>
<% end %>
<div id="tiles">
<%= render "tile", tile: { type: "sam", id: "0" } %>
<%= render "tile", tile: { type: "inputs", id: "1" } %>
<%= render collection: #tiles, partial: "tile" %>
<%= render "tile", tile: { type: "social", id: "1000" } %>
</div>
+
This is the console log:
log/development.log
Started GET "/" for 127.0.0.1 at 2017-08-31 16:56:28 -0400
Processing by TilesController#index as HTML
Started GET "/" for 127.0.0.1 at 2017-08-31 16:56:28 -0400
Processing by TilesController#index as HTML
[1m[36mProject Load (0.5ms)[0m [1m[34mSELECT "projects".* FROM "projects" ORDER BY "projects"."launch_date" ASC LIMIT $1[0m [["LIMIT", 10]]
[1m[36mProject Load (9.1ms)[0m [1m[34mSELECT "projects".* FROM "projects" ORDER BY "projects"."launch_date" ASC LIMIT $1[0m [["LIMIT", 10]]
Rendering tiles/index.html.erb within layouts/application
Rendered tiles/_tile_sam.html.erb (0.3ms)
Rendered tiles/_tile.html.erb (8.0ms)
Rendering tiles/index.html.erb within layouts/application
Rendered tiles/_tile_sam.html.erb (0.0ms)
Rendered tiles/_tile.html.erb (0.9ms)
Rendered tiles/_tile_instagram.html.erb (12.6ms)
...
Rendered tiles/_tile_twitter.html.erb (0.5ms)
Rendered collection of tiles/_tile.html.erb [48 times] (125.9ms)
Rendered tiles/_tile_project.html.erb (0.1ms)
Rendered tiles/_tile_social.html.erb (0.6ms)
Rendered tiles/_tile.html.erb (2.7ms)
Rendered tiles/index.html.erb within layouts/application (166.1ms)
Rendered tiles/_tile_twitter.html.erb (0.6ms)
...
Rendered collection of tiles/_tile.html.erb [48 times] (158.5ms)
Rendered tiles/_tile_social.html.erb (0.1ms)
Rendered tiles/_tile.html.erb (1.0ms)
Rendered tiles/index.html.erb within layouts/application (165.3ms)
Completed 200 OK in 1310ms (Views: 217.1ms | ActiveRecord: 9.1ms)
Completed 200 OK in 1325ms (Views: 204.5ms | ActiveRecord: 0.5ms)
Help!

Answer 1

WOW
Finally figured this one out by removing code related to this action/view line by line. Basically, I was generating a few img tags with empty src fields. Apparently this causes many modern browsers to load a website several times, possibly in an attempt to find missing images or assuming the root URL is the image itself?
Found the behavior cited here:
https://forums.asp.net/t/1804472.aspx?Bizzare+safari+thing+two+page+loads+for+each+page+
page loads twice in Google chrome