To upgrade your Steam Engine ruin, you need Steam Engine Shards.
With each upgrade, you need more Steam Engine Shards.
Below is a list of possible ways to gain these.
Gems
You can purchase Steam Engine Shards using gems.
1 Steam Engine Shard = 15 Gems
10 Steam Engine Shards = 125 Gems
100 Steam Engine Shards = 1,154 Gems
1000 Steam Engine Shards = 10,000 Gems
Chest
You can purchase a chest using guild coins to have a chance at
gaining extra Steam Engine Shards.
To purchase, click bag, click chests, click the third icon on right hand side.
The chest is called Magical Shard Box and costs 22,500 Guild Coins.
It randomly gives you 10 shards for any of the ruins or statues.
Campaign Elite Sweeps
You can sweet elite campaigns to pick up extra Steam Engine shards.
Elite 4-1
Elite 4-2
Elite 4-3
Elite 4-4
Elite 4-5
Elite 4-6
Chests
Chest from the VIP daily clan gifts (Steambeard city) gives Steam Engine shards too.
VIP Daily Clan Gifts
You can collect 3 Steam Engine shards per gift from daily VIP Clan gifts (Once you have level 25 diplomacy for this city).